Minimally invasive no touch (MINT) procedure for harvesting the great saphenous vein (GSV) and venous hydrodissector and retractor for use during the mint procedure

ABSTRACT

A hydrodissector for hydrodissecting a vascular target, the hydrodissector comprising: a handle; a shaft extending from the handle at an angle and including a tip at a distal end thereof; at least one port provided at the tip and configured to be coupled to a fluid supply and to eject fluid from the at least one port into the space between the vascular target and surrounding tissues to dissect the vascular target from the surrounding tissues, the at least one port being sized to provide sufficient pressure and velocity to dissect the vascular target from the surrounding tissues, wherein the length of the shaft is configured for insertion into an incision to atraumatically hydrodissect the vascular target from the surrounding tissues, and wherein the shaft is configured to releasably couple with one or more hook-shaped attachments configured to lift the vascular target after the vascular target is dissected from the surrounding tissues.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.16/208,915 filed on Dec. 4, 2018, which is a divisional of U.S. patentapplication Ser. No. 16/039,115 filed on Jul. 18, 2018 and issued asU.S. Pat. No. 10,687,793 on Jun. 23, 2020, which claims the benefit ofU.S. Provisional Application Nos. 62/533,714 filed on Jul. 18, 2017,62/640,892 filed on Mar. 9, 2018 and 62/683,376 filed on Jun. 11, 2018.The entire disclosures of these applications are incorporated herein byreference.

INTRODUCTION

There are currently two vascular epidemics present in the population ofthe United States. Atherosclerosis directly leads to coronary arterydisease (CAD), which is the leading cause of death in the United Statestoday. Coronary artery bypass grafting (CABG) may be described simply asa procedure for bypassing severely damaged or non-functional coronaryarteries using a grafted portion of a healthy vein or artery harvestedfrom the patient under treatment, such as the great saphenous vein(GSV), explained in greater detail below. Atherosclerosis also is thecause of peripheral arterial disease (PAD), which leads to significantdisability, increased amputation rates, and death. A second epidemicwhich is present in the United States is a very high incidence ofsignificant varicose veins.

SUMMARY OF THE INVENTION

This patent application discloses an improvement over the knownendoscopic vein harvest (EVH) methods presently used to harvest the GSVfor use in CABG procedures in a way that increases long term patency ofthe grafted portions as well as an improvement in the treatment ofvaricose veins that preserves the GSV in the body of the patient undertreatment so that it will be available in an optimized state forharvesting in the future, if required.

In certain embodiments of the invention, a minimally invasive method fordissecting a greater saphenous vein (GSV) from surrounding tissues isprovided. The method comprises inserting one of a needle and ahydrodissector into a patient's body so that a tip of the one of theneedle and the hydrodissector is placed in a predetermined positionadjacent to the GSV to be dissected from surrounding tissues, andinjecting fluid at a substantially constant volumetric flow rate fromthe one of the needle and the hydrodissector while moving the one of theneedle and the hydrodissector along a predetermined length of the GSV tocause dissection of the GSV from the surrounding tissues, whereinhydrodissected GSV is suitable for subsequent harvesting for use insurgical bypass procedures. In certain embodiments, the predeterminedposition adjacent the GSV is 1-2 mm away from an upper surface of theGSV closest to the patient's skin or 1-2 mm away from a lower surface ofthe GSV furthest from the patient's skin.

In certain embodiments, the fluid injected in the injecting stepcomprises tumescent fluid including one or more of: isotonic sodiumbicarbonate solution, Balanced Salt Solution with a pH of 7.4, isotonicsaline solution, Plasma Lyte A solution, and an endothelial damageinhibitor solution comprising glutathione, ascorbic acid and L-arginine.In certain embodiments, the tumescent fluid further comprises one ormore medications including one or more of: aspirin, low-molecular weightheparin, one or more vasodilators, nitroglycerine, Endothelin A receptorantagonist, folic acid, angiotensin II receptor antagonist, Spermine/NO,Losartan, Perilyl alcohol, Superoxide dismutase, Antitissue factorantibody, Verapamil, Ursolic acid, Rapamycin, Azathioprin, Paclitaxel,C-type natriuretic peptide, Leoligin, Papaverine, platelet rich plasmaand stem cells. In some embodiments, these medications may be applied tothe GSV after performing the hydrodissection.

In some embodiments, the GSV is hydrodissected from the surroundingtissues using one or more needles, and the inserting and injection stepsare successively performed for each of a plurality of portions of alength of the GSV to cause dissection the respective portion of thelength of the GSV from the surrounding tissues. In some embodiments, aplurality of needles are used, and each respective portion of the lengthof the GSV is hydrodissected from the surrounding tissues using arespective one of the plurality of needles.

In certain embodiments, the steps of inserting and injecting areperformed under one or more of: (1) ultrasound guidance for visualizingthe one of the needle and the hydrodissector and (2) direct vision ofthe one of the needle and the hydrodissector using an image capturingdevice provided on or in proximity with the one of the needle and thehydrodissector. The ultrasound guidance for visualizing one of theneedle and hydrodissector may be performed using a portable ultrasounddevice. When direct vision is used, the direct vision may be obtained bycapturing live images using the image capturing device provided at thetip of the hydrodissector.

In certain embodiments, the minimally invasive method further comprises,before performing the inserting and injecting steps, making an incisionin a patient's extremity; and positioning a barrier with an access portthrough the incision so as to cover and seal the incision, wherein theinserting step comprises inserting the one of the needle and thehydrodissector through the access port into the predetermined positionadjacent the GSV to be dissected from the surrounding tissues. In someembodiments, the barrier is formed from fluid-tight material andcomprises one of a diaphragm and a tissue occluder, and the access portcomprises a fluid-tight one way valve.

The present invention is also directed to a surgical bypass method thatincludes the above minimally invasive method, and further includesharvesting the hydrodissected GSV by exposing the hydrodissected GSV,dividing side branches of the hydrodissected GSV and dividing proximaland distal ends of the hydrodissected GSV, and using harvested GSV forbypass surgery. In some embodiments, the harvesting step furthercomprises lifting the hydrodissected GSV after exposing thehydrodissected GSV and prior to dividing the side branches.

The present invention is also directed to an ambulatory selectivevaricose vein ablation method comprising the above minimally invasivemethod and further including exposing the hydrodissected GSV; andligating incompetent perforator and varicosed vein side branches. Theambulatory selective varicose vein ablation method may further includeapplying drug eluting stents to the hydrodissected GSV and ligated veinside branches for delivering one or more of drug therapy, stem celltherapy and gene therapy to the GSV.

The present invention is further directed to harvesters andhydrodissectors used for the above methods. In some embodiments, theinvention provides a harvester for harvesting a vein, the harvestercomprising a handle, a blade extending at an angle from the handle, andone or more hook-shaped attachments configured to couple with the bladeso as to protrude from a surface of the blade, the one or morehook-shaped attachments being configured for lifting of a vein during avein harvesting procedure. The hook-shaped attachment may be a C-shapedattachment or a U-shaped attachment, and may be detachable from theblade. In certain embodiments, the blade includes a plurality ofcoupling mechanisms along a length of the blade, each of the couplingmechanisms being configured to selectively couple with one of thehook-shaped attachments. In some embodiments, the blade has a firstsurface facing away from the handle and an opposing second surface, andthe one or more hook-shaped attachments are configured to couple to thefirst surface of the blade. In other embodiments, the blade comprises atubular shaft and a spoon-shaped tip at a distal end of the tubularshaft and the one or more hook-shaped attachments are configured tocouple to one or more of the tubular shaft and the spoon-shaped tip.

The harvester of the present invention may also include one or moreports provided at the distal end of the tubular shaft, each of the oneor more ports is configured to be coupled to one of a fluid supply, agas supply and a vacuum. In some embodiments, the harvester furtherincludes an image capturing assembly for capturing images of anoperating field, with the image capturing assembly including an imagecapturing device provided at a tip of the blade. The tip of the blademay be spoon-shaped including a concave surface and an opposing convexsurface, and the image capturing device may be provided on the concavesurface of the spoon-shaped tip.

In another embodiment, the present invention provides a harvester forharvesting a vein, the harvester comprising a handle, a blade extendingat an angle from the handle and having a spoon-shaped tip at a distalend of the blade, the spoon-shaped tip including a concave surface and aconvex surface, and an image capturing assembly for capturing images ofan operating field, the image capturing assembly including an imagecapturing device provided on the concave surface of the spoon-shapedtip.

In yet another embodiment, the present invention provides a harvestingretractor for harvesting a vein, which includes a handle, a bladeextending at an angle from the handle and having a first surface facingaway from the handle and an opposing second surface, and a tunnel formedon the first surface of the blade and extending along a portion of theblade configured for accommodating a direct visualization devicetherein. The harvesting retractor may also include a channel along thefirst surface of the blade and a channel cover covering the channel,wherein the channel is configured for one or more of: removal of fluidsfrom operating field, removal of debris from the operating field,removal of smoke from the operating field, injecting fluid into theoperating field and infusing gas into the operating field, and whereinthe channel and the tunnel extend along the first surface of the bladeand are parallel to one another.

The present invention also provides a hydrodissector for hydrodissectinga vein, the hydrodissector comprising a handle, a shaft extending fromthe handle at an angle and including a tip at a distal end thereof, atleast one port configured to be coupled to a fluid supply for supplyingfluid at a substantially constant pressure, and provided at the distalend of the shaft, and an image capturing assembly configured to providedirect visualization of the vein during hydrodissection. In certainembodiments, the image capturing assembly comprises an image capturedevice encased by the tip of the shaft. The image capture deviceincludes a lens, an image sensor and/or one or more light sources. Theimage capturing assembly may also include a power source for poweringthe image capture device, said power source being provided in one of thetip, the shaft and the handle.

In certain embodiments, the tip of the shaft is transparent and theimage capture device is positioned inside the tip so that an opticalaxis of the image capture device is angled relative to a lengthwise axisof the tip so as to allow direct viewing of the vein to behydrodissected. In some embodiments, the tip has a substantiallycylindrical shape and an angled end so that a first surface of the tipis longer than an opposing second surface of the tip.

In certain embodiments, the at least one port is external and adjacentto the first surface of the tip, while in other embodiments, the atleast one port is provided in the tip and is configured to be coupledthe fluid supply via one of the shaft and a conduit extending inside theshaft. The at least one port may include a first port configured to becoupled to a fluid supply and having a size between 14 and 22 gauge, andin some embodiments, a second port may be provided for coupling to avacuum.

In certain embodiments, the tip is configured to rotate relative to theshaft. In some embodiments, the shaft is configured to rotate relativeto the handle. In some embodiments, the tip of the shaft is removablefrom a body of the shaft and interchangeable with one or more secondtips, while in other embodiments the shaft is removable from the handleand interchangeable with one or more second shafts. The second tip maybe a spoon-shaped tip configured for retracting tissues and forharvesting the vein, and a second image capturing device may be providedon the spoon-shaped tip. The second shaft may include a second tip, suchas a spoon-shaped tip, and may be configured to releasably couple withthe handle and to convert the hydrodissector into a harvester forharvesting the vein, and may have a second image capturing device isprovided on the second tip.

The above features of the invention as well as the features recited inthe claims are interchangeable and may be combined and used in anyconfiguration with one another. Further features and advantages will beapparent to those skilled in the art after reviewing the drawings anddetailed description provided herein.

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1 -A-1B show a process of hydrodissecting the GSV using one needleto hydrodissect multiple sections of the GSV;

FIGS. 2A-2B show another process of hydrodissecting the GSV using oneneedle to hydrodissect multiple sections of the GSV;

FIGS. 3A-3B show another process of hydrodissecting the GSV usingmultiple needles to hydrodissect respective sections of the GSV;

FIG. 4 shows another process of hydrodissecting the GSV using a venoushydrodissector;

FIGS. 5A-5C show an exemplary venous hydrodissector for use in theprocess of FIG. 4 ;

FIG. 6 shows a retractor for use during harvesting the GSV;

FIG. 7 shows another version of a retractor for use during theharvesting of the GSV;

FIGS. 8A and 8B show a front view of different versions of the retractorof FIG. 7 ;

FIG. 9A shows a GSV after undergoing an endoscopic ASVAL procedure;

FIG. 9B shows a GSV after undergoing the Endoscopic ASVAL procedure andhaving bioabsorbable drug eluting stents applied thereto;

FIG. 10 shows an exemplary visualization device that uses a pediatriccystoscope;

FIG. 11 shows a 7F introducer sheath suitable for use with thevisualization device of FIG. 10 ;

FIG. 12 shows the visualization device used with the introducer sheath;

FIG. 13 shows an end portion of the visualization device extendingthrough an end of the introducer sheath and fluid being pumped throughthe introducer sheath around the visualization device;

FIG. 14 shows a retractor of the present invention used with thevisualization device of FIG. 10 ;

FIG. 15 shows a side view of another exemplary hydrodissector for usewith the procedure shown in FIG. 4 ;

FIG. 16 shows a close-up of the side view of the hydrodissector of FIG.15 at its distal end;

FIG. 17 shows a cross-sectional view of the hydrodissector's tip, takenalong a dashed line in FIG. 16 ;

FIG. 18 shows an end view of the hydrodissector of FIG. 15 in situ,surrounded by connective tissue above the GSV;

FIG. 19 shows an end view of the hydrodissector of FIG. 15 in situ whiledissecting connective tissue off the underlying GSV;

FIGS. 20A-20C show another exemplary version of the hydrodissector foruse with the procedure shown in FIG. 4 ;

FIGS. 21A-21C show another exemplary version of the hydrodissector foruse with the procedure shown in FIG. 4 ;

FIGS. 22-25 show another version of the procedure for hydrodissectingthe GSV; and

FIG. 26 shows an exemplary split screen visualization which includes anultrasound view of hydrodissection and a direct visualization view.

DETAILED DESCRIPTION Minimally Invasive No Touch (Mint) Procedure forCABG and Lower Extremity Bypass

Since its introduction in 1967 by Renee Favalaro, coronary artery bypasssurgery (CABG) has saved the lives of millions of patients with coronaryartery disease (CAD). As originally described, CABG was performed byharvesting the great saphenous vein (GSV) via a longitudinal incisionover the entire length of the GSV, referred to as the open vein (OVH)technique. The OVH technique, however, resulted in a significantincidence of leg wound complications, including bleeding, hematoma,infection, amputation and death. In the mid-1990's, a minimally invasiveharvesting technique was developed to reduce leg wound complicationscalled endoscopic vein harvest (EVH). EVH employs the techniques ofminimally invasive surgery to harvest the GSV. Specifically, the EVHtechnique employs a 2 cm incision at the level of the knee. The GSV isexposed through this incision and bluntly dissected from its surroundingconnective tissue, including a well-developed laminar ligament whichattaches the GSV to the underlying muscular fascia. This laminarligament has been anatomically well defined and arises from theadventitia of the GSV. While EVH has greatly reduced the incidence ofleg wound complications, several recent articles have suggested that thepatency rates of the GSV harvested by EVH are inferior to thoseharvested by the open vein technique (OVH).

Concurrent with the development of EVH, Dr. Domingos R Souza, Departmentof Cardiovascular and Thoracic Surgery, Örebro University Hospital,Örebro, Sweden, has developed a so called “No Touch” technique forharvesting the GSV. In this technique, the GSV is harvested with a cuffof surrounding tissue so that the GSV itself is never touched during theharvesting procedure. This technique has resulted in five year patencyrates of 90% for this vascular conduit, which is equivalent to theresults obtained when utilizing the internal thoracic artery (ITA),which is considered to be the gold standard of vascular conduits forCABG. Unfortunately, this technique is technically demanding and resultsin local leg wound complications as high as 50%. As a result, thistechnique has not been widely adopted.

Therefore, a need exists for a venous harvesting technique that improvespatency rates of the harvested GSVs without wound complications andwithout requiring extensive training in adopting the technique. Theminimally invasive no touch (MINT) procedure of the present inventionprovides these advantages by effectively improving the patency rates ofharvested GSVs without the local leg wound complications associated withthe known “No Touch” harvesting technique. The MINT procedure alsoprovides for visualization of the vein during dissection and harvesting,thereby reducing or eliminating a risk of damaging the harvested GSV andmaking it easy for physicians to acquire the skill of harvesting theGSV.

The MINT procedure utilizes the technique of hydrodissection tofacilitate the harvesting of the GSV. It should be noted that the MINTprocedure, including the hydrodissection and the harvesting of the GSV,can be readily applied to harvesting the GSV for CABG and for lowerextremity bypass procedures.

Hydrodissection is a technique that has been used in microsurgicalprocedures such as DIEP flaps, robotic prostatectomy and dissection ofITA for CABG. It has been established that hydrodissection facilitatesmicrovascular dissection while not affecting the patency of themicrovascular pedicle itself. One difficulty in using hydrodissectionfor harvesting the GSV is the laminar ligament which attaches the GSV tothe underlying muscular fascia and which typically requires a bluntforce to divide it. For example, the blunt force necessary to dividethis ligament during the EVH procedure likely contributes to endothelialdamage to the GSV, which can result in reduced patency rates. In orderto minimize or eliminate any endothelial damage done to the GSV, theMINT procedure contemplates performing hydrodissection several hours andpreferably, several days, prior to harvesting the GSV at the time ofCABG. Doing so allows for recovery of any endothelial damage done at thetime of the hydrodissection. However, in those patients with a need foran emergency bypass, hydrodissection can be performed immediately beforeharvesting and excess fluid remaining after hydrodissection can bemilked or suctioned from the tunnel along the GSV before harvesting theGSV.

In greater detail, the inventive improved MINT procedure includesbringing the candidate for CABG surgery to the catheterization lab (oran associated venous treatment facility) several hours and preferably,several days prior to the actual harvesting of the GSV. The candidate isplaced with the lower extremity in a frog leg position and thensubjected to duplex scanning of the GSV to be hydrodissected andutilized. Ultrasonic equipment may be used for evaluating the GSV and totrace its course using a marker, e.g., Sharpie® marking pen. Afterconfirming that the GSV is of significant caliber and quality to beutilized, the lower extremity is prepped and sterilized withChlorhexidine prep. Hydrodissection of the GSV is then carried out undersonographic control, such as by ultrasound guidance, using a needle,such as a 20 gauge or 22 gauge echogenic spinal needle and an infusionpump, or using a venous hydrodissector with a blunt tip or a pencil tipand an opening at the end, or a venous hydrodissector as described belowand shown in FIGS. 10-13 and 15-21 . After the GSV is hydrodissected,the GSV is exposed using a harvester (or retractor) described in moredetail herein below, and is harvested by exposing and dividing sidebranches of the GSV and by dividing proximal and distal ends of the GSV.

During hydrodissection, needle visualization or venous hydrodissectorvisualization using ultrasound is used in order to insert the needleinto a “sweet spot” in the extremity near the GSV without making contactwith the GSV. The “sweet spot” is a predetermined position into which atip of the needle or hydrodissector is inserted and is preferably about1-2 mm distance away from the wall of the GSV. In other embodiments, thedistance from the GSV may be smaller or greater than 1-2 mm. In certainembodiments, the “sweet spot” is located at or near the upper surface ofthe GSV, i.e., surface closest to the patient's skin, i.e., at a 12o'clock location, while in other embodiments, the “sweet spot” islocated to the side of the upper surface of the GSV, i.e., at about20-90 degrees away from a plane connecting the center of the GSV and thetop surface of the GSV in either direction (or between 9 o'clock and 12o'clock or between 12 o'clock and 3 o'clock), and preferably at an angleof around 30-60 degrees from the plane connecting the center and the topsurface of the GSV. Although the “sweet spot” may include other surfacesof the GSV, the top and side surfaces of the vein are the preferredlocations because the GSV is held tightly to the fascia by a ligament.Since the GSV is surrounded by the fascia, needle or venoushydrodissector localization and placement of the needle or venoushydrodissector in the “sweet spot” is important so that fluid to beinjected flows only into desired areas around the GSV. When multiplehydrodissection passes are performed along the length of the GSV, asecond or subsequent hydrodissection pass may be performed with a second“sweet spot” being adjacent to the lower surface of the GSV, i.e., at oraround a 6 o'clock location, which is opposite to the to the upper ortop surface of the GSV. Alternatively, the first pass may be performedwith the “sweet spot” being adjacent to the lower surface of the GSV andthe second or subsequent pass may be performed with the second “sweetspot” being adjacent to the upper surface of the GSV. In certainembodiments, the second “sweet spot” may be to the side of the lowersurface of the GSV (between 6 o'clock and 9 o'clock or between 6 o'clockand 3 o'clock).

Fluid used during hydrodissection is tumescent fluid, such as isotonicsodium bicarbonate with or without lidocaine, Balanced Salt Solutionwith a pH of around 7.4, such as Hank's Balanced Salt Solutionmanufactured by Thermo Fisher Scientific Isolyte Solution, or isotonicsaline solution and/or any other suitable tumescent fluid solution. Insome embodiments, the tumescent fluid is DuraGraft (GALA Solution namedafter Glutathione, Ascorbic acid, L-Arginine) endothelial damageinhibitor solution manufactured by Somahlution, Inc. based in Jupiter,Fla. DuraGraft is used for tissue preservation in the GSV specificallyfor CABG, and is a preferred solution for performing the hydrodissectionin order to reduce endothelial damage during this procedure. Examples ofa GALA solution and a Hank's Balanced Salt Solution suitable for use astumescent fluid during hydrodissection are disclosed in U.S. Pat. No.7,981,596. In certain embodiments, tumescent fluid includes one or moremedications for protecting the GSV and assisting in healing of the GSV.These one or more medications include one or more of aspirin, whichprotects the endothelium, heparin, such as local low-molecular weightheparin, and one or more vasodilators, such as venous vasodilators orcombination dilators. Other medications that can be included in thetumescent fluid include but are not limited to one or more of thefollowing: Nitroglycerine, Endothelin A receptor antagonist, Folic Acid,Angiotensin II receptor antagonist, Spermine/NO, Losartan, Perilylalcohol, Superoxide dismutase, Antitissue factor antibody, Verapamil,Heparin, Ursolic acid, Local Aspirin, Rapamycin, Azathioprin,Paclitaxel, C-type natriuretic peptide, Leoligin and Papaverine. In someembodiments, tumescent fluid may include platelet rich plasma or stemcells for strengthening the wall of the GSV, and in certain embodiments,gene therapy may be used as part of the tumescent fluid.

When used for performing hydrodissection of the GSV, the use of theabove-mentioned solutions should greatly reduce the initial learningcurve for inexperienced Physicians Assistants, as well as improve thepatency of the GSV when grafted. That is, even in experienced hands,this inventive MINT procedure should greatly eliminate the amount ofblunt trauma resulting in endothelial dysfunction at the time ofharvesting.

In some embodiments, the GSV is hydrodissected completely from thesurrounding fascia. Complete hydrodissection may be necessary when theharvesting of the vein is performed immediately or shortly after thehydrodissection. In order to completely hydrodissect the GSV from thesurrounding fascia, it may be necessary to perform multiple passes ofhydrodissection along the length of the GSV, e.g., two passes ofhydrodissection. For example, in a first hydrodissection pass, theneedle or the hydrodissector is inserted into the “sweet spot” at oraround the upper surface of the GSV (at or around 12 o'clock) and theGSV is hydrodissected by moving the needle or the hydrodissector alongthe upper surface of the GSV. The first hydrodissection pass willhydrodissect at least the upper half of the GSV (from 9 o'clock to 3o'clock). In order to ensure that the GSV is completely hydrodissectedaround the lower half of the GSV, the second hydrodissection pass may beperformed by placing the needle or hydrodissector in the second “sweetspot” at or around the lower surface of the GSV (at or around 6o'clock), which is opposite to the “sweet spot” at the upper surface sothat the needle and the dissector is between the GSV and the muscularfascia. The second hydrodissection pass proceeds by moving the needle orthe hydrodissector along the lower surface of the GSV until the GSV islifted off the muscular fascia. As discussed above, the locations of the“sweet spot” and the second “sweet spot” may be reversed or may beprovided at different locations relative to the GSV.

However, in other embodiments, the GSV is partially hydrodissected sothat all surrounding fascia is dissected from the vein except thelaminar ligament, which can be dissected at a later time, under directvision. In certain embodiments, the partially hydrodissected GSV remainstethered to some of the surrounding tissues. Partial hydrodissection ofthe GSV may result in less damage to the vein, thus extending theutility of the GSV and reducing its failure rate. Any remaining tissuecan be hydrodissected under direct vision with either a spinal needle orvenous hydrodissector.

As mentioned above, ultrasound guidance is used for needle or venoushydrodissector localization and during hydrodissection. After the needleor venous hydrodissector is inserted and fluid is injected, the fluidmakes a pocket around the GSV and the GSV may move during thehydrodissection. Ultrasound guidance allows the user to see the pocketforming around the vein and to see the tip of the needle or venoushydrodissector to ensure that the needle or venous hydrodissector doesnot damage the GSV. In some embodiments of the invention, portableultrasound equipment is used for the ultrasound guidance. For example,Terason® t3200 or t3300 Ultrasound System with Enhanced NeedleVisualization (ENV) may be used for ultrasound guidance and for needlelocalization during the hydrodissection. The ENV helps the user toinsert the needle or venous hydrodissector close to the GSV withoutcoming into contact with the GSV.

When hydrodissection is performed using one or more needles, a needle isinserted into the lower extremity and the needle tip is visualized usingultrasound guidance. In the present illustrative embodiment, the “sweetspot” for hydrodissection using one or more needles is at the top of theGSV and about 1 mm away from the wall of the GSV. However, in otherembodiments, the “sweet spot” may be off to the side of the GSV.

Once the needle tip is visualized in the “sweet spot”, fluid is injectedat high pressure to hydrodissect the GSV from the surrounding connectivetissue. In this illustrative embodiment, a predetermined length of theGSV, e.g., about 10 cm of the GSV, is hydrodissected, after which theneedle is removed, inserted at the next section of the GSV to behydrodissected, the needle tip is visualized under ultrasound guidance,and after the needle tip is visualized in the “sweet spot,” fluid isagain injected at high pressure to hydrodissect another predeterminedlength of the GSV. This process is repeated until the entire length ofthe GSV is hydrodissected. In hydrodissecting each section of the GSV,the amount of fluid may be determined based on time of performing thehydrodissection, wherein the fluid is pumped at a constant volumetricflow rate (e.g., ml/m or ml/s). In the illustrative embodiment of theinvention, about 100 ml of fluid is injected for about every 10 cm ofthe GSV being hydrodissected. In such embodiments, typicallyhydrodissection is performed 3 or 4 times along the length of the GSV,injecting between about 300 ml and 400 ml of fluid. Hydrodissectionusing one or more needles may be performed using one needle, such as an18 gauge needle, a 20 gauge needle or a 22 gauge needle, e.g. 22 gaugeechogenic spinal needle or an introducer needle with a 1/50 inchopening, or using multiple needles of similar size, wherein each needleis used for hydrodissecting a separate predetermined length of the GSV.The size of the needle is not limited to 18, 20 or 22 gauge sizes andother sizes may be used as long as sufficient fluid pressure is providedfor hydrodissection. For example, the size of the needle may be between14 gauge and 22 gauge.

The process of hydrodissecting the GSV using one or more needles isillustrated in FIGS. 1A-1B, 2A-2B and 3A-3B. As shown in FIGS. 1A-1B,one needle 104 is used for hydrodissection to hydrodissect fourconsecutive sections of the GSV 102. In FIGS. 1A-1B, the needle 104 isinserted into each consecutive section of the GSV 102 in accordance withthe circled numbers 1-4, from the knee area and up to the groin area.FIG. 1B illustrates insertion of the needle 104 into the “sweet spot”adjacent to the GSV 102 prior to injecting the fluid to dissect the GSVfrom surrounding connective tissue. In FIGS. 2A-2B, the order ofinsertion of the needle 104 into each consecutive section of the GSV 102is opposite of FIG. 1A, starting from the groin area to the knee area.The insertion of the needle 104 into the “sweet spot” adjacent the GSV102 in FIG. 2B is similar to that of FIG. 1B. In FIGS. 3A-3B, fourneedles are used for hydrodissection of four consecutive sections of theGSV 102. As shown in FIG. 3A, all four needles 104 are inserted into the“sweet spot” as shown in FIG. 3B, after which the fluid is injectedthrough each needle to hydrodissect the corresponding section of the GSVfrom the surrounding connective tissue. Although FIGS. 1A-3B showhydrodissection being performed on the GSV between the knee area and thegroin area, it is understood that the same hydrodissection procedure mayalso be performed between the knee area and the ankle of the lowerextremity, and may be performed along the entire length of the GSV. Itis also understood that the number of sections of the GSV is not limitedto 3 or 4 and may be greater depending on the length of the GSV beinghydrodissected. Moreover, as described above, multiple hydrodissectionpasses may be made where needed in order to achieve sufficientdissection of the GSV.

Alternatively, hydrodissection may be performed by passing a narrowpencil-tip or a blunt-tipped venous hydrodissector under ultrasoundguidance in the “sweet spot” through a small incision in the lowerextremity and by pumping fluid, e.g., tumescent fluid, at high pressurethrough an opening at the tip of the venous hydrodissector tohydrodissect the GSV from surrounding connective tissues. In certainembodiments, the incision for inserting the venous hydrodissector isformed around the knee area. In this way, the hydrodissection procedurerequires only one incision for hydrodissecting the entire length of theGSV, including a portion between the knee area and the groin area and aportion between the knee area and the ankle area. In some embodiments,the “sweet spot” for inserting the venous hydrodissector is about 1 mmaway from the GSV wall and at a location off to the side of the GSV,such as about 20-90 degrees in either direction from a plane connectingthe top surface of the GSV and the center of the GSV. This way, thevenous hydrodissector is introduced along the side of the veintransversely, reducing possibility of damage to the GSV.

In some embodiments, the venous hydrodissector is introduced into theincision and after the venous hydrodissector tip is visualized in the“sweet spot,” fluid is injected at high pressure through the opening inthe venous hydrodissector to hydrodissect the GSV from the surroundingconnective tissue. During hydrodissection, the venous hydrodissector isslid up along the GSV while injecting the fluid until the venoushydrodissector is fully inserted into the lower extremity along the GSV.After performing hydrodissection on one of the portions of the GSV,i.e., either the portion between the knee and the groin area or theportion between the knee and the ankle, the venous hydrodissector isremoved and the same hydrodissection process may be performed on theother portion of the GSV through the same incision until the wholelength of the GSV has been hydrodissected. In other embodiments, thevenous hydrodissector may be introduced into the incision and fullyinserted along the GSV to the other end of the GSV before visualizingthe venous hydrodissector tip in the “sweet spot” and thereafterinjecting fluid. In such embodiments, after the fluid is injected, theGSV is hydrodissected by pulling the venous hydrodissector back alongthe GSV. Similarly, both portions of the GSV may be hydrodissectedthrough the same incision made in the knee area. As in thehydrodissection using one or more needles, the amount of fluid may bedetermined based on the amount of time of performing thehydrodissection, wherein the fluid is pumped at a constant volumetricflow rate (e.g., ml/m or ml/s). In the illustrative embodiment of theinvention, about 100 ml of fluid is injected for about every 10 cm ofthe GSV being hydrodissected, with around 300-400 ml of fluid injectedfor each portion of the GSV that is hydrodissected.

The process of hydrodissecting the GSV using a venous hydrodissector isillustrated in FIG. 4 . As shown, a blunt tipped venous hydrodissector204 is used for hydrodissection to hydrodissect the one of two sectionsof the GSV 202. The venous hydrodissector 204 is inserted into a smallincision, which is preferably formed in the knee area, and slid alongthe GSV 202 before placing the tip of the venous hydrodissector in the“sweet spot” and pumping tumescent fluid to hydrodissect the GSV fromthe surrounding tissue. In this case, the venous hydrodissector 204 isslowly pulled out through the incision while hydrodissecting the GSV.Alternatively, the venous hydrodissector 204 may be inserted into theincision and once the venous hydrodissector 204 tip is visualized in the“sweet spot”, the fluid is pumped to hydrodissect the GSV while slidingthe venous hydrodissector 204 further along the GSV. Although FIG. 4shows the venous hydrodissector being inserted at the top of the GSV, inother embodiments, the venous hydrodissector is inserted along the sideof the GSV, at an angle between 20 and 90 degrees from the planeconnecting the center and the top of the GSV. As described above,multiple hydrodissection passes may be made where needed in order toachieve sufficient dissection of the GSV, and in a secondhydrodissection pass, the hydrodissector is visualized in the second“sweet spot” which is on the opposite side of the GSV from the “sweetspot” during the first hydrodissection pass (e.g., around 180 degreesrelative to the “sweet spot” during the first hydrodissection pass).

An example of a pencil tip venous hydrodissector suitable forhydrodissecting the GSV is shown in FIGS. 5A-5B. The venoushydrodissector may be disposable or may be reusable. The venoushydrodissector 204 has an elongated hollow substantially cylindricalbody 206 and a pencil tip with a small opening 206 a therein. The lengthof the venous hydrodissector body 206 can be between 10 and 30 cm long,and preferably between 15-25 cm long. The body of the venoushydrodissector may be made from metallic materials, such as stainlesssteel or titanium, or from polymers and/or plastics with sufficientstrength. The venous hydrodissector 206 also includes a port 208 at theother end to which an infusion pump for pumping the fluid can beconnected. The port 208 can be a standard port, e.g., a Luer Lock port,to which any standard infusion pump may be coupled, or can be any othertype of port. FIG. 5B shows a close-up of the tip of the venoushydrodissector, showing a small opening 206 a formed at the tip. Theopening 206 a should be small enough to create sufficient pressure whenthe fluid is pumped therethrough. For example an opening sized betweenabout 0.01 and 0.1 inches in diameter is suitable, and preferablybetween 0.01625 and 0.06 inches in diameter (14-22 gauge in size). Inone illustrative embodiment, the opening 206 a is about 0.02 inches toabout 0.04 inches in diameter. In another illustrative embodiment, theopening is between 0.01625 and 0.024 inches in diameter. FIG. 5C shows aclose-up view of another venous hydrodissector tip which has acone-shaped blunt tip. Like in FIG. 5B, the venous hydrodissector tip inFIG. 5C includes a small opening formed at the tip which is sized tocreate sufficient fluid pressure when fluid is pumped therethrough.

In certain embodiments, a venous hydrodissector with a wider body and alarger opening at tip may be used in combination with a needle. In suchembodiments, the needle is inserted into the venous hydrodissector sothat the tip of the needle is covered by the tip of the venoushydrodissector. The needle may be 14 gauge to22 gauge in size, similarto the needle size used for the hydrodissection with a needle or adifferent size (gauge) needle. The infusion pump is connected to theneedle and pumps the fluid through the needle and out of the tip of thevenous hydrodissector. This arrangement provides for sufficient fluidpressure to hydrodissect the GSV from the surrounding tissue whileprotecting the GSV from inadvertent damage by using the venoushydrodissector near the wall of the GSV.

The inventive hydrodissection techniques are optimized by use of theabove-described venous hydrodissector. The venous hydrodissector isconfigured with a pencil tip shaped or a cone-shaped tip and only oneoutflow port in the center of the tip in in order to ensure that thehydrodissection implemented by use of the venous hydrodissector occursin parallel to the GSV.

Using the above-described venous hydrodissector minimizes force vectorsthat might result off-angle from the axial center of the linear extentof the GSV, for example, at 90° or less which is likely in conventionalor standard infusion cannulas, which are known to have one or moreoutflow ports arranged in the cannula shaft, which create fluid pathssubstantially perpendicular to the cannula longitudinal axis. Fluidtypically exits from these conventional ports creating force vectorsperpendicular or slightly less than perpendicular to the longitudinalaxis. The venous hydrodissector, therefore, reduces trauma that thehydrodissection procedure might impose on or to the GSV.

Although the hydrodissection procedure described above is performedunder ultrasound guidance, it is also possible to perform theabove-described hydrodissection of the GSV under direct vision insteadof using ultrasound guidance. Direct vision of the hydrodissectionprocedure can be achieved by using a visualization device comprising athin tube with a camera and a light source provided at one end andcapable of connecting to a display panel (e.g., a tablet, a TV, amonitor, etc.) either using a wire or wirelessly. In certainembodiments, the diameter of the tube is about 2 mm or smaller. In someembodiments, a port for infusion of liquid may be included in thevisualization device, which is used as a hydrodissector, while in otherembodiments, no such port is included in order to reduce the diameter ofthe tube. In certain embodiments, a pediatric cystoscope, an angioscopeor an endoscope may be used as the visualization device. It is desiredfor the visualization device to be capable of capturing and transmittingclear images when exposed to liquids. An example of a suitablevisualization device, which is a pediatric cystoscope, is shown in FIG.10 , or a hydrodissector shown in FIGS. 15-19 . An example of a suitableangioscope is an Olympus 2 mm angioscope. In this way, the MINTprocedure can be performed utilizing currently available urologic orvascular equipment.

In the embodiments that use direct vision when performinghydrodissection, the patient is first prepped and draped in the usualfashion with the donor lower extremity in the frog leg position. First,about 30 ml of tumescent fluid is injected inside the fascial envelope.In some embodiments, the tumescent fluid is injected just above the GSV,i.e., at 12 o'clock position, while in other embodiments, the tumescentfluid may be injected to the side of the GSV. This injection of thetumescent fluid can be performed either percutaneously with ultrasoundguidance, such as by using a portable ultrasound device, or under directvision via a small incision, e.g., about 2 cm incision, that exposes theGSV. If a percutaneous injection is performed, the GSV is then exposedvia a small incision, e.g., standard 2-3 cm incision, just below thetumescent fluid collection.

Using a syringe with a needle, such as a 10 mL syringe with a 21 gaugespinal needle, the fluid collection is entered while keeping the needleand syringe parallel to and just above the exposed GSV. After the fluidis aspirated, a guide wire is passed into the fluid space and anintroducer sheath, such as a 7F introducer sheath, is placed into thefluid space. FIG. 11 shows a 7F introducer sheath suitable for use inthis procedure. As shown, the introducer sheath includes a side portwhich can be used for pumping fluid through the introducer sheath, asdescribed in more detail below.

After the introducer sheath is placed, the visualization device, such asa 2 mm pediatric cystoscope shown in FIG. 10 or a 2 mm angioscope, ispassed into the fluid space via the introducer sheath. FIG. 12 shows a 2mm cystoscope inserted into the 7F introducer sheath and demonstratesthe positioning of the cystoscope relative to the 7F introducer sheath.When the visualization device, e.g., cystoscope or angioscope, isconnected to a display device, either by a wire or wirelessly, the GSVis visualized directly on the monitor using the visualization device,e.g., cystoscope or angioscope. This technique allows thehydrodissection of the GSV to be performed under direct vision in realtime. After the introducer sheath and the visualization device, e.g.,cystoscope or angioscope, are positioned, hydrodissection can beperformed using one of the following techniques.

In a first technique, the side port of the introducer sheath is attachedto an infusion pump and fluid is infused via the introducer sheath at asufficiently high rate to hydrodissect the GSV. Hydrodissection isperformed by moving the assembly of the visualization device with theintroducer sheath, while pumping fluid along the length of the GSV or aportion of the GSV. FIG. 13 shows an end portion of the visualizationdevice extending through an end of the introducer sheath, and fluidbeing pumped through the introducer sheath around the visualizationdevice. The visualization device allows the hydrodissection to beperformed under direct vision in real time and eliminates the need forultrasound guidance.

In one example, a 7F introducer sheath like the one shown in FIG. 11 anda 2 mm cystoscope as shown in FIG. 10 or a 2 mm angioscope are used forperforming hydrodissection of the GSV. The size match of the 7Fintroducer and the 2 mm cystoscope/angioscope diameter allows justenough room for the fluid to travel in the sheath and around thecystoscope/angioscope and to exit the sheath as a jet of fluid withsufficient pressure to hydrodissect the GSV. In addition, there is noback up or leaking of fluid. In this technique, the hydrodissection ofthe GSV is performed using a single assembly of the visualization devicewith the introducer sheath, with the assembly being advanced together asa unit along the GSV. In certain embodiments, the hydrodissection isperformed by advancing the cystoscope/angioscope and introducer sheathassembly proximally toward the groin. However, in other embodiments, thedirection in which the hydrodissection is performed may be changed.

In a second technique of performing hydrodissection, the hydrodissectionof the GSV is performed using a needle or the venous hydrodissector, asdescribed above, with the fluid being pumped through the needle or thevenous hydrodissector, and using the visualization device with theintroducer sheath for direct visualization of the GSV and of the needleor the venous hydrodissector. The configuration of the needle or venoushydrodissector used in this variation of the hydrodissection procedureis the same as described above. For example, the hydrodissection may beperformed percutaneously using a needle, such as a 22 gauge spinalneedle, under direct vision using the visualization device with theintroducer sheath. This hydrodissection technique is similar to thehydrodissection technique described above using one or more needles orusing the venous hydrodissector, but instead of ultrasound guidance,this procedure is performed under direct vision.

In a third technique, a needle or a venous hydrodissector is attached tothe visualization device lengthwise, so that the visualization deviceand the needle or the venous hydrodissector extend side by side withinthe introducer sheath. The configuration of the needle or venoushydrodissector used in this variation of the hydrodissection procedureis the same as described above. The needle or the venous hydrodissectoris attached to an infusion pump so as to pump fluid therethrough. Forexample, a 20 or 22 gauge blunt tipped spinal needle can be attachedlengthwise to a 2 mm cystoscope. The hydrodissection of the GSV in thistechnique is performed by advancing the visualization device with theattached needle or venous hydrodissector along the GSV as the fluid isbeing pumped, while leaving the introducer sheath in place. As in thefirst and second techniques, the hydrodissection of the GSV is performedunder direct vision via the venous hydrodissector in real time.

Other types of hydrodissectors 1200 (or dissectors) that can be used forhydrodissection of the GSV are shown in FIGS. 15-21 . Thehydrodissectors of FIGS. 15-21 provide direct visualization of the GSVduring hydrodissection by capturing and transmitting live images of theGSV and surrounding areas during the procedure.

FIG. 15 shows a general side view of the hydrodissector 1200 with ahandle 1210. As shown, the hydrodissector 1200 includes an elongatedtubular-shaped body 1220 having a proximal end 1220 a to which thehandle 1210 is coupled and a distal end 1220 b to which an angled tip1230 is coupled. The angled tip 1230 is preferably formed from plastic,polymer material, glass, acrylic glass, e.g., poly(methylmethacrylate),Plexiglass, etc., or other suitable materials, and is transparent ortranslucent. The body 1220 can be formed from a metallic material, e.g.,stainless steel, aluminum, titanium, etc., or from a suitable plastic orpolymer material. Similarly, the handle 1210 can be formed from plasticor polymer material or may be formed from metal or any other suitablematerial.

The angled tip 1230 has a substantially cylindrical shape and has anangled end so that a lower surface (first surface) of the tip 1230 islonger than an upper surface (second surface) of the tip 1230. Theangled end of the tip 1230 is preferably sealed or closed so as toprevent fluids and debris from entering the angled tip 1230 through theangled end. However, in other embodiments, the angled end of the tip1230 may be partially sealed/closed or may be open. In the illustrativeembodiment shown in FIGS. 15-19 , the lower surface of the tip 1230would be positioned closer to the GSV than the upper surface during thehydrodissection procedure.

In order to allow the lower surface of the angled tip 1230 (longersurface of the angled tip) to be positioned closer to the GSV than theopposing upper surface during the hydrodissection procedure, theorientation of the angled tip 1230 relative to the orientation of thehandle 1210 may be adjustable. In certain embodiments, the handle 1210can be rotated around the tubular-shaped body 1220 and can be locked inone or more orientations, or the tubular-shaped body 1220 can be rotatedrelative to the handle 1210. The locking orientations of the handle 1210may be flexible to allow an operator to select any suitable orientation,or the locking orientations of the handle 1210 may be predetermined soas to limit the number of orientations of the handle 1210 relative tothe tubular-shaped body 1220. For example, in the hydrodissector of FIG.15 , one locking orientation may be as shown in FIG. 15 where the handleis oriented in the same direction as the upper surface of the angled tip1230, and another locking orientation may be 180 degrees around thetubular-shaped body so that the handle 1210 is oriented in the samedirection as the lower surface of the angled tip 1230. Additionallocking orientations may be provided in the hydrodissector. In certainembodiments, the angled tip 1230 may be rotated relative to thetubular-shaped body 1220 and may be locked in one or more orientations,which may be predetermined or may be flexible so as to be selectable bythe operator. Rotating the handle 1210 and/or the angled tip 1230 aroundthe tubular-shaped body 1220 allows the hydrodissector 1220 to be usedto hydrodissect the GSV along the upper surface of the GSV, i.e., alongthe surface closest to the patient's skin, and to hydrodissect the GSValong the lower surface of the GSV, i.e., along the surface adjacent themuscular fascia.

FIG. 16 shows a close-up of the side view of the hydrodissector 1200 atits distal end and FIG. 17 shows a cross-sectional view of thehydrodissector's angled tip 1230 taken along a dashed line in FIG. 16 .As shown in FIGS. 16 and 17 , the hydrodissector 1200 includes at leastone fluid port 1240 for injecting fluid therethrough to hydrodissect theGSV as described above. The at least one fluid port 1240 includes aconduit that extends along the tubular-shaped body 1220 and is coupledto a fluid supply at a proximal end thereof (not shown) and has aninjection opening 1241 at a distal end thereof. The proximal end of theconduit of the fluid port 1240 may have a Luer Lock fitting or any othersuitable fitting at its end to allow the fluid port 1240 to be connectedto the fluid supply, e.g., tumescent fluid supply, gas supply, e.g., CO2supply, and/or vacuum source. The injection opening 1241 is preferablylocated at or near the angled end of the angled tip 1230.

In some embodiments, as shown in FIG. 17 , the hydrodissector 1200includes two fluid ports 1240 a, 1240 b including conduits that extendsubstantially parallel to one another along the tubular-shaped body1220. The conduit of each port may have a Luer Lock fitting or any othersuitable fitting at its proximal end for connection to fluid supply, gassupply and/or vacuum source. The fluid ports 1240 a, 1240 b may have thesame size or may have different sizes from one another, and the sizes ofthe ports may vary between 14 and 22 gauge. In the illustrativeembodiment shown in FIG. 17 , the fluid port 1240 a is smaller than thefluid port 1240 b, with the fluid port 1240 a having a 20 gauge sizeopening and the fluid port 1240 b having a 14 gauge size opening. Inthis illustrative embodiment, the fluid port 1240 a is used forinjecting tumescent fluid for hydrodissecting the GSV, as describedabove, and the fluid port 1240 b is used for suction of tumescent fluidafter hydrodissection of the GSV. However, in other embodiments, thesmaller sized port may be used for suction of fluid while the largersized port is used for injection of fluid, or the ports may have thesame size. In the embodiment of FIG. 17 , the conduits of the ports 1240a, 1240 b are provided along a lower outer surface of the tubular-shapedbody 1220 and along the outer lower surface of the angular tip 1230.Specifically, the ports 1240 a, 1240 b are spaced from one another sothat each port 1240 a, 1240 b is provided along a different side of thelower outer surface of the tubular-shaped body 1220 and along adifferent side of the lower surface of the angled tip 1230. In otherembodiments, the ports 1240 a, 1240 b may be provided along the sameside of the lower outer surface of the tubular-shaped body 1220 and thelower surface of the angled tip 1230. In certain embodiments, one orboth of the ports may include a sealing or closing mechanism to closethe port opening when not in use. In this way, when one of the ports isbeing used to inject fluid to hydrodissect the GSV, the fluid isprevented from escaping though the other port.

Certain embodiments may include only one port 1240, instead of twoports, for supplying fluid for hydrodissection of the GSV. In suchcases, the conduit of the single port may extend along the lower outersurface of the tubular-shaped body 1220 and along the lower surface ofthe angled tip 1230 and may be centered or may be shifted to one of thesides relative to the tubular-shaped body and the tip. The positioningof the port depends on the position of an image capture device 1250 andis made such that the port does not block the field of view of the imagecapture device.

As also shown in FIGS. 16 and 17 , the hydrodissector 1200 includes theimage capture apparatus 1250, such as a video camera or the like,disposed inside the angled tip 1230. By placing the image captureapparatus 1250 inside the angled tip 1230, the image capture apparatus1250 is protected from fluids and debris during the hydrodissection ofthe GSV. As mentioned above, in certain embodiments, the angled end ofthe angled tip 1230 is closed or sealed, and thus, in such embodiments,the image capture apparatus 1250 is encapsulated or encased in theangled tip and protected from fluids and debris. The image captureapparatus 1250 is configured to capture live images so as to visualizethe GSV during the hydrodissection procedure. The live images may betransmitted wirelessly from the image capture apparatus 1250 to acomputer, a tablet or a suitable display, or may be transmitted througha wire, e.g., by a USB connection.

The image capture apparatus is preferably an miniature camera so that itcan be fitted within the angled tip 1230. The image capture apparatusmay be a waterproof or non-waterproof, CMOS-based video camera withencapsulated lighting. In one example, the camera is a HD waterproofendoscope video camera probe with a small diameter of less than 1 inch,e.g., about 0.1-0.5 inch diameter, that includes a Hi-Vision or SuperHi-Vision CMOS sensor and has a resolution of 2.0 MP or higher. Thecamera preferably has a focal distance between 0.5 and 4 inches.However, the focal distance of the camera may vary depending on itsconfiguration and desired position within the angled tip 1230. Thecamera of this example includes one or more of a USB-C connection, aMicro USB connection, a Bluetooth® connection and/or a Wi-Fi connectionfor connecting with an external display, computer or tablet. In otherexamples, the camera may be a miniature cystoscope, angioscope orlaparoscope camera. In certain examples, the camera may be compatiblewith any operating system, such as Windows 7/8/10, Mac OS, Androidsystem, etc. and may support a USB On-The-Go (USB OTG or OTG) and USBvideo device class (UVC) functions. In certain embodiments, the camerauses a lens carrier housing for enclosing the lens, and image sensorchip and/or lighting, such as the endoscope video cameras, and the lenscarrier housing is attached to a surface of the angled tip of thehydrodissector or positioned within the angled tip. In otherembodiments, the camera may be a one-piece assembly that incorporatesthe lens, the image sensor chip and/or the lighting, which can be moldedinto the angled tip or received in a cavity formed in the angled tip ofthe hydrodissector.

As shown, the image capture apparatus 1250 is positioned at an anglewith respect to the lower surface of the angled tip 1230, i.e., anoptical axis of the camera is at an angle with respect to the lowersurface of the angled tip 1230, so that a camera lens and a camerasensor are provided at an angle with respect to the line of sight to theGSV which underlies the lower surface of the angled tip duringhydrodissection. The angle of the image capture apparatus 1250 may bebetween 15 and 60 degrees relative to the lower surface of the angledtip 1230. In the illustrative embodiment of FIG. 16 , the image captureapparatus 1250 is positioned at about a 30 degree angle relative to thelower surface of the angled tip 1230. This angled positioning of theimage capture apparatus 1250 allows for direct viewing of the GSV to behydrodissected and during the hydrodissection procedure. The angle ofthe image capture apparatus 1250 relative to the lower surface of theangled tip 1230 will depend on the distance of the image capture device1250 from the injection opening 1241 of the fluid input port 1240 a andthe field of view of the image capture apparatus 1250. Although notshown in FIGS. 16 and 17 , the angled tip 1230 may also have one or morelight sources, e.g., one or more LEDs, disposed therein. For example, aplurality of LEDs may be disposed around the image capture apparatus1250, or at least one LED may be disposed adjacent to the image captureapparatus 1250. In some embodiments, the LEDs are angled relative to thelower surface of the angled tip 1230 similarly to the image captureapparatus 1250 so as to direct light emitted from the LEDs in the samedirection as the object being captured by the image capture apparatus1250. Also not shown in FIGS. 15-17 are one or more power sources forpowering the image capture apparatus 1250 and/or the light source(s) andany connections or wiring necessary for connecting the power source(s)to the image capture apparatus 1250 and/or the light source(s) and forconnecting the image capture apparatus 1250 with a display, a computeror tablet, if needed. In some embodiments, the image capture apparatus1250 may include an internal power source, while in other embodiments,the power source may be disposed within the tubular-shaped body 1220 orwithin the handle 1210. The connections or wiring to the power sourceand/or to the display, computer or tablet may be provided through thetubular-shaped body 1220 and/or through the handle 1210.

FIGS. 18 and 19 show the hydrodissector of FIGS. 15-17 being used duringhydrodissection of the GSV along the top surface of the GSV. As shown inFIG. 18 , the hydrodissector is surrounded by the connective tissue justabove the GSV. As discussed above, to hydrodissect the GSV, thehydrodissector is placed in the “sweet spot”, with the angled tip 1230being preferably just above the top surface of the GSV, e.g., a fewmillimeters above the GSV, and the image capture apparatus 1250 is usedfor directly visualizing the hydrodissector 1200 in the “sweet spot” andfor directly visualizing the GSV and the surrounding area. After thehydrodissector of FIGS. 15-17 is placed in the “sweet spot,” fluid isinjected through one of the fluid ports 1240 a or 1240 b as shown inFIG. 19 so as to dissect the connective tissue off the GSV. Thehydrodissector 1200 is moved along the length of the GSV whiledissecting the connective tissue off the GSV in order to hydrodissectthe entire length of the GSV. As mentioned above, the GSV may behydrodissected using multiple hydrodissection passes, so that during thesecond hydrodissection pass, the hydrodissector 1200 is visualizedadjacent the lower surface of the GSV, which is opposite to the uppersurface of the GSV shown in FIGS. 18 and 19 , and then fluid is injectedthrough one of the fluid ports of the hydrodissector, while moving thehydrodissector along the lower surface of the GSV to dissect themuscular fascia from the GSV. Before using the hydrodissector 1200 forthe second hydrodissection pass, the handle 1210 or the angled tip 1230of the hydrodissector is rotated about 180 degrees relative to thetubular body so that during the second hydrodissection pass, the lower(longer) surface of the angular tip 1230 faces the GSV.

FIGS. 20A-20C and 21A-21C show other versions of the hydrodissector 1200that can be used for hydrodissecting the GSV. The hydrodissector 1200 inFIGS. 20A-20C and 21A-21C is modified by providing the one or more ports1240 that include conduits inside the tubular-shaped body 1220. FIGS.20A and 21A show a close-up side view of the hydrodissector 1200 nearits distal end, and in each of these embodiments, the hydrodissector1200 includes the tubular-shaped body 1220, the angled tip 1230 attachedto the distal end of the tubular-shaped body 1220, the image captureapparatus 1250 provided inside and enclosed by the angled tip 1230 andone or more ports 1240 for fluid supply, gas supply and/or vacuum. As inthe embodiment of FIGS. 15-19 , the image capture apparatus 1250 isprovided at an angle between 15 and 60 degrees relative to the lowersurface of the angled tip 1230. The conduits of the one or more ports1240 are provided within the tubular-shaped body 1220 and the differencebetween the embodiment of FIG. 20A-C and FIG. 21A-C is the configurationof the one or more ports 1240.

As shown in FIG. 20A, the conduits of the one or more ports 1240 extendalong the lower inner surface of the body 1220 and along the inner lowersurface of the angled tip 1230. An opening 1242 is provided for eachport at the end of the angled tip 1230. FIGS. 20B and 20C showcross-sectional views of the hydrodissector 1200 in FIG. 20A taken alongthe dashed line in FIG. 20A. FIG. 20B shows a cross-sectional view of ahydrodissector with one port 1240, and FIG. 20C shows a cross-sectionalview of a hydrodissector with two ports 1240 a and 1240 b. The ports1240, 1240 a, 1240 b preferably have an opening of 14-22 gauge in size.In FIG. 20B, the port 1240 is preferably a fluid port for supplyingtumescent fluid for hydrodissection of the GSV and has a size between 14and 22 gauge, and preferably, 20 or 22 gauge. In FIG. 20C, the ports1240 a, 1240 b may have the same size or may have different sizes. Forexample, port 1240 a may be used as a fluid port for supplying tumescentfluid for hydrodissection of the GSV and may have a size between 14 and22 gauge, and preferably, 20 or 22 gauge. The port 1240 b may be used asa suction port and may have a larger size between 14 and 22 gauge, andpreferably between 14 and 18 gauge. In certain embodiments, the port1240 a may be used for suction and the port 1240 b may be used for fluidsupply and may be sized as needed for these functions. In certainembodiments, one or both of the ports 1240 a, 1240 b may be closed orsealed when not in use in order to prevent fluid from entering theunused port during the hydrodissection procedure.

As shown in FIGS. 20B and 20C, the port 1240 or the ports 1240 a, 1240 bare disposed on the inner lower surface of the angled tip 1230 and areshifted to the side away from the center. In FIG. 20C, both ports may beprovided on the same side instead of being on different sides of theangled tip 1230. In any case, the ports 1240, 1240 a, 1240 b arepositioned so as not to block the field of view of the image captureapparatus 1250 through the lower surface of the angled tip 1230.

In FIGS. 21A-21C, the hydrodissector 1200 has one or more ports 1240including conduits which extend along the lower inner surface of thetubular-shaped body 1220 and along a portion of the angled tip 1230.Each port 1240 is then directed through an opening 1243 in the lowersurface of the angled tip 1230 to outside of the hydrodissector 1200.The end of the port 1240 may extend downwardly from the opening or maybe angled toward the distal end of the hydrodissector, as shown in FIG.21A. Although FIG. 21A shows the port 1240 extending through the opening1243 in the lower surface of the angled tip 1230, in other embodiments,the opening may be provided in the lower surface of the tubular body1220 and the port 1240 would extend through the opening in the tubularbody 1220. The position of the opening would depend on the desiredposition of fluid injection from the hydrodissector 1200 during thehydrodissection procedure.

FIGS. 21B and 21C show cross-sectional views of the hydrodissector 1200in FIG. 21A taken along the dashed line in FIG. 21A. FIG. 21B shows aconfiguration of the hydrodissector 1200 with one port 1240, while FIG.21C shows a configuration of the hydrodissector 1200 with two ports 1240a, 1240 b. As in FIGS. 20B and C, the ports 1240, 1240 a, 1240 b areshifted to the side away from the center so as not to block the view ofthe image capture apparatus 1250 through the angled tip 1230. In FIGS.21B and 21C, port sizes and uses are similar to those of FIGS. 20B and20C and thus, detailed description thereof is omitted.

Although the embodiments of FIGS. 20A-21C show at least one port 1240extending along the lower surface of the body 1220 and the angled tip1230, in other embodiments, fluid may be supplied directly to thetubular-shaped body 1220, without using a separate structure for theport, and a small opening may be provided in the angular tip for fluidinjection therefrom. The opening size should be such that fluid isinjected from the opening with sufficient fluid pressure forhydrodissection of the GSV. The opening size may be between 14 and 22gauge and preferably, 20 or 22 gauge. The opening may be provided at theend of the angled tip, similar to FIG. 20A or may be provided in thelower surface of the angled tip, similar to FIG. 21A.

Although FIGS. 15-17 and 20A-21C show the hydrodissector that uses theangled tip 1230, in other embodiments, the angled tip 1230 may beremovable from the body 1220 and may be interchangeable with other typesof tips attachable to the body 1220. Different tips may be used fordifferent phases of the procedure, e.g., angled tip 1230 forhydrodissection of the GSV and other types of tips for harvesting of theGSV. In certain embodiments, the angled tip 1230 may be removable fromthe body 1220 and may be replaced with a shovel-shaped or spoon-shapedtip. An example of a shovel-shaped or spoon-shaped tip is shown in FIGS.7, 8A and 8B, which show the shovel-shaped or spoon-shaped tip beingused on a harvesting retractor. In such cases, the camera and/or anylight sources are held in the shovel-shaped or spoon-shaped tip, e.g.,on the concave surface of the shovel-shaped or spoon-shaped tip, whichprovides partial protection for the camera and/or light source(s) fromfluids and debris. The camera and/or light source(s) may be positionedso as to face in a direction away from the handle and toward a distalend of the dissector (e.g., at about 90 degrees relative to the lowersurface of the tip) or may be angled to face away from the concavesurface of the shovel-shaped or spoon-shaped tip (e.g., at an anglebetween 90 and 180 degrees relative to the lower surface of the tip). Insuch embodiments, the camera may use a lens carrier housing thatencloses the lens, the image sensor chip and/or lighting (e.g., LEDs)and the lens carrier is attached, either permanently or detachably, tothe concave surface of the spoon-shaped tip. In yet other embodiments,the camera may be a one-piece assembly that incorporates the lens, theimage sensor chip and/or the lighting, which can be molded into thespoon-shaped tip or received in a cavity formed in the spoon-shaped tip.

As in the embodiment of FIGS. 15-17 , the port(s) in this embodiment areprovided along the lower surface of the shovel-shaped or spoon-shapedtip (along the convex surface thereof) and any wiring or connections andpower source(s) are provided within the body 1220 and/or the handle1210. Alternatively, the fluid port(s) may be provided along the insidesurface of the body 1220, similar to the embodiments of FIGS. 20A and21A, and may be passed to the outside through an opening in the body1220.

In certain embodiments, instead of interchangeable tips which can beremoved from the body 1220 and changed as needed, the body 1220 of thehydrodissector is releasable and removable from the handle, and can bereplaced with a different body having a different tip. For example, thebody 1220, i.e., shaft, of the hydrodissector of FIGS. 15-17 thatincludes the angled tip, may be removable from the handle andinterchangeable with a second body, i.e., shaft, with a different tip,such as a shovel-shaped or spoon-shaped tip, to be attached to thehandle. This configuration of the hydrodissector, where the bodytogether with the tip, is interchangeable, avoids removal and changingof small parts on the hydrodissector during or in between surgicalprocedures.

The dissector with the shovel-shaped or spoon-shaped tip thereon, orwith the second body having the shovel-shaped or spoon-shaped tip, maybe used as a retractor or harvester during the harvesting of the GSV, asdescribed in more detail below. Similar to the retractor shown in FIGS.6 and 7 , and described below, one or more C-shaped and/or U-shapedattachments may be releasably attached to the shovel-shaped orspoon-shaped tip or to the body 1220 of the dissector. In addition, asin the retractor of FIGS. 6 and 7 , the tip and/or the body 1220 mayhave multiple coupling positions for selectively coupling or clipping onthe C-shaped and/or U-shaped attachments at different locations.

When the venous hydrodissector of FIGS. 5A-5C, the visualization deviceof FIGS. 10-13 or the hydrodissectors of FIGS. 15-19, 20A-C and 21A-Care used for hydrodissecting the GSV, the above-describedhydrodissection procedure may be modified as shown in FIGS. 22-26 inorder to provide a fluid-tight insertion access site to the GSV throughan incision. The modified hydrodissection procedure of FIGS. 22-26 mayalso be used when the tumescent fluid is injected using one or moreneedles. As shown in FIG. 22 , a 3 cm or similar size incision is madeat the knee of the patient, and as shown in FIG. 23 , a small circularor elliptical diaphragm 2300 or a suitable tissue occluder with aone-way valve 2310 or access port is placed through the incision tocover and seal the incision made in FIG. 22 . The diaphragm may be madeof rubber or similar fluid-tight and malleable material. The one-wayvalve 2310 is water-tight so as to prevent leakage of tumescent fluidinjected into the incision during hydrodissection. As shown in FIG. 24 ,the hydrodissector 2400, such as the visualization device of FIGS. 10-13or the hydrodissector of FIG. 5A-5C, 15-19, 20A-C or 21A-C, is placedthrough the access port 2310 and thereafter directed to the “sweet spot”adjacent the top surface of the GSV. The hydrodissection procedure isthen performed as described above by injecting tumescent fluid tohydrodissect the GSV from the surrounding fascia and moving thehydrodissector along the top surface of the GSV to accomplishhydrodissection of the entire length of the GSV.

As discussed above, in certain embodiments, multiple hydrodissectionpasses may be needed to achieve sufficient hydrodissection of the GSVfrom the surrounding fascia. In certain cases, when hydrodissection ofthe GSV is performed as shown in FIGS. 22-24 , at least the upper halfof the GSV from about 9 o'clock to about 3 o'clock is hydrodissectedfrom the surrounding fascia. In order to ensure that the lower half ofthe GSV is completely hydrodissected from 3 o'clock to 9 o'clock, thesecond hydrodissection pass may be performed along the lower surface ofthe GSV. Prior to performing the second hydrodissection pass, the handle1210 or the angled tip 1230 of the hydrodissector shown in FIGS. 15-21Cis rotated about 180 degrees and locked in this orientation so that whenthe hydrodissector is used for the second hydrodissection pass, theimage capture apparatus in the angled tip 1230 faces the GSV to providedirect visualization of the GSV. As shown in FIG. 25 , thehydrodissector 2400 is placed through the access port 2310 in thediaphragm and directed to the second “sweet spot” adjacent the lowersurface of the GSV (at or around the 6 o'clock position). In thisposition, the angled tip 2430 of the hydrodissector 2400 is positionedbetween the GSV and the muscular fascia to which the GSV is attached.The second hydrodissection pass then proceeds in a controlled fashion byinjecting tumescent fluid from the hydrodissector and with the imagecapture apparatus facing the GSV, i.e., looking up at the GSV at 6o'clock, as the GSV is being lifted off the muscular fascia. The secondhydrodissection pass ensures complete hydrodissection of the GSV fromthe surrounding fascia and eliminates the need for use of a needle totouch up the hydrodissection.

In certain embodiments, in addition to the direct visualization providedby the hydrodissector using a camera, ultrasound guidance may be used inorder to place the tip of the hydrodissector in the “sweet spot” and toadvance the hydrodissector along the GSV. In such cases, an ultrasoundprobe used for ultrasound guidance is connected to the same or differentdisplay unit, computer or tablet as the camera of the hydrodissector.When the ultrasound probe and the camera of the hydrodissector areconnected to the same display unit, computer or tablet, a split screenis displayed showing live images from the camera and ultrasound imagesfrom the ultrasound probe. In this way, the operator can control thedissection of the GSV by keeping the hydrodissector right over the GSVand also watching the fluid form a halo around the GSV using theultrasound probe. As mentioned above, portable Terason® ultrasounddevices may be used for ultrasound guidance during hydrodissection. FIG.26 shows an exemplary split screen visualization which includes anultrasound view of hydrodissection on a left screen portion and directvisualization on a right screen portion. After the hydrodissection ofthe GSV is complete, the hydrodissector is removed and the fluid isevacuated. Alternatively, prior to removing the hydrodissector, fluidsupply is turned off and suction is turned on via a suction port of thehydrodissector in order to evacuate the fluid. In this case, thehydrodissector is removed after evacuating the fluid.

The above described hydrodissection of the GSV procedures allow the GSVto be dissected from the surrounding fascia without damaging the GSV.Moreover, the saphenous nerve runs along the GSV and is often damaged byconventional techniques, resulting in loss of a sensory function.Hydrodissection of the GSV completely dissects the saphenous nerve fromthe GSV, without damaging the nerve, and as a result, sensory functionof the extremity is not affected. In experienced hands, the GSVhydrodissection procedure takes less than 10 minutes to perform. In thistechnique, a catheter in the GSV is not required to render the GSVechogenic and thus easy to visualize during hydrodissection. Therefore,the above-described hydrodissection is performed without a catheterpresent in the GSV.

As discussed above, the hydrodissection procedure also requires that asufficient amount of tumescent fluid is injected around the GSV so thatthe vein is surrounded by a dark halo of fluid (when viewed using u/s orunder direct vision) without any echogenic connective tissue. Thisensures that at the time of GSV harvest for CABG, the only attachmentsof the GSV will be its branches which have also been hydrodissected fromthe surrounding connective tissue. This is possible because in a closedspace such as the fascial envelope surrounding the GSV, the force vectorof the fluid creating the hydrodissection travels along the path ofleast resistance which is the interface between the adventitia of theGSV and its branches and the surrounding connective tissue.

Moreover, by hydrodissecting the GSV, the hydrodissected GSV may be usedas a drug-delivery system by applying one or more medications orsolutions to the adventitia or the outer wall of the GSV. The one ormore medications or solutions may be applied to the GSV duringhydrodissection by including one or more medications in the tumescentfluid, as described above, or by separately applying the one or moremedications to the hydrodissected GSV after performing thehydrodissection. As discussed above, in some embodiments, medications toprotect the GSV and to heal the GSV may be applied to the hydrodissectedGSV, and in particular, to the adventitia of the hydrodissected GSV,including aspirin, which protects the endothelium, heparin, such aslocal low-molecular weight heparin, and one or more vasodilators, suchas venous vasodilators or combination dilators. Other medications mayinclude but are not limited to one or more of the following:Nitroglycerine, Endothelin A receptor antagonist, Folic Acid,Angiotensin II receptor antagonist, Spermine/NO, Losartan, Perilylalcohol, Superoxide dismutase, Antitissue factor antibody, Verapamil,Heparin, Ursolic acid, Local Aspirin, Rapamycin, Azathioprin,Paclitaxel, C-type natriuretic peptide, Leoligin and Papaverine.Characteristics and use of these medications is described in more detailin “Perivascular administration of drugs and genes as a means ofreducing vein graft failure” by Wiedemann, et al., published by CurrentOpinion in Pharmacology 2012, 12:203-216. In some embodiments, plateletrich plasma or stem cells may be used to strengthen the wall of the GSV.In certain embodiments, gene therapy may be used on the GSV.

As discussed above, ideally, hydrodissection of the GSV is performedseveral hours or one or two days prior to the harvesting of the GSV andthe actual bypass surgery. For harvesting of the GSV and the bypasssurgery, the patient is prepped and draped in a standard fashion, andthe hydrodissected GSV is exposed through an incision in the knee area.A retractor (also referred to as a “harvester”) described below can beused to expose the GSV so as to allow for visualization of the GSV inorder to allow harvesting of the GSV. Alternatively, as discussed above,the hydrodissector described above with respect to FIGS. 15-17 and withthe shovel-shaped or spoon-shaped tip may be used for harvesting theGSV. During the harvesting procedure, the retractor or harvester is usedto expose the GSV and to lift the GSV so that exposed side branches ofthe GSV can be divided. Specifically, the side branches of the GSV aredivided with a bipolar cautery device or using hemoclips or scissors.Thereafter, proximal and distal ends of the GSV are also divided so asto allow the harvested GSV to be used for bypass surgery.

FIGS. 6, 7, 8A and 8B illustrate a retractor or harvester which may beused during the GSV harvesting procedure. The retractor is preferably adisposable retractor. However, in some embodiments, the retractor may bereusable. FIG. 6 shows one embodiment of the retractor or harvester,while FIGS. 7 and 8A-8B show another variation of the retractor of FIG.6 , which has a different blade and tip configuration. Both retractorsof FIG. 6 and of FIGS. 7 and 8A-8B may be used for harvesting as shownin FIG. 7 .

As shown in FIG. 6 , the retractor 600 includes a handle 602 and a blade604 extending at an angle from the handle 602. The retractor 600 mayinclude a curved section 603 connecting the handle 602 to the blade 604.

The blade 604 of the retractor 600 is of sufficient length to beinserted along the dissected GSV so as to expose the GSV and itsbranches. For example, the length of the blade 604 may be between 10 and30 cm. In one example, the length of the blade is around 25 cm, while inanother example, the blade is 15 cm in length. The width of the bladecan be between 1 and 5 cm, and preferably between 2 and 4 cm. In oneexample, the width of the blade 604 is 2 cm, while in another example,the width of the blade is 4 cm. As shown in FIG. 6 , the blade 604 alsoincludes a tip 604 a, which in FIG. 6 is shown as a substantiallyrectangular tip angled relative to the rest of the blade 604. Theconfiguration of the tip 604 a of the blade 604 may be varied and is notlimited to the one shown in FIG. 6 . For example, the tip 604 a may havea rounded shape or may have a triangular shape with the sidewallsconverging to a narrower tip or to a point. In another example, the tipmay be shovel-shaped or spoon-shaped, as shown in FIGS. 7 and 8A-8B. Insome examples, the tip 604 a may include a lip at its end, orprojections or an in-molded pattern to assist in holding back thetissue. In other variations, the end of the tip 604 a may be smooth. Inyet other examples, the tip 604 a may be aligned with the rest of theblade 604 instead of being angled.

The blade 604 has a first surface 604 b which faces an inside of thepatient when in use and a second surface 604 c which faces the outsideof the patient when in use. The retractor 600 also includes a channelformed along the first surface 604 b of the blade 604 and extendingthrough the handle 602 of the retractor to a port 608. The channelincludes a channel cover 606 that covers at least a portion of thechannel extending along the first surface 604 b of the blade 604 andwhich is coupled with the handle and/or may extend into the handle. Theconfiguration of the channel and the channel cover 606 may be similar tothe smoke evacuation channel used in a retractor described in U.S. Pub.Nos. US 2016/0354072 and 2017/0245849 and U.S. application Ser. No.15/869,994, all of which are assigned to the same assignee herein andare incorporated herein by reference. In the retractor of the presentinvention, the channel can be used for removal of fluid, debris and/orsmoke as well as for providing fluid into the incision and the opencavity. For example, the channel may be used for washing the GSV withfluid, such as the sodium bicarbonate solution or a solution of one ormore medications mentioned above, and/or for providing a CO₂ infusion tothe GSV.

In certain embodiments, particularly those that use the channel forconducting liquids and for supplying liquids to the patient cavity, theconstruction of the channel is made airtight and/or watertight so as toprevent the fluids from leaking into and possibly damaging othercomponents of the retractor, e.g. electrical components. For example, inorder to ensure watertight construction, the channel may include a tube,a conduit or a similar fluid conveying member extending from the port608 in the handle and through the length of the handle 602. The tube mayalso extend under the cover 606 along at least a portion of the lengthof the blade 604. In other embodiments, the cover may engage with theblade 604 in an airtight manner and extend into the handle to fluidlycouple with the tube or similar device passing through the handle to theport 608. As can be appreciated, the port 608 can be connected to afluid supply and/or an infusion pump for supplying the fluid, e.g., CO₂,sodium bicarbonate solution, medication solution, etc. Additionally, theport 608 can be connected to a vacuum source when suction from thecavity is needed.

As shown in FIG. 6 , the retractor also includes one or more U-shapedattachments 610 which are releasably attached to the blade 604 so as toprotrude from the first surface 604 b of the blade. In the illustrativeembodiment of FIG. 6 , a single U-shaped attachment is provided near thedistal end of the blade 604. However, it is understood that the positionof the U-shaped attachment may be varied, and may be changed from oneposition to another depending on the needs of the user. In someembodiments, multiple U-shaped attachments may be used if desired.

Multiple coupling mechanisms may be provided along the length of theblade 604 so as to allow desired positioning of the U-shapedattachment(s) along the length of the blade. As shown in FIG. 7 , theU-shaped attachment is used to gently lift and hold the hydrodissectedGSV. This allows for holding and exposing the perivenous space with onehand. As can be seen in FIG. 7 , the tip 604 a of the blade 604 isinserted into the incision to expose the hydrodissected GSV. Afterinserting the tip of the blade 604 into the incision and exposing theGSV, the U-shaped attachment can be snapped or clipped onto the bladeand around the GSV so as to allow the retractor to gently raise the GSVto separate it from the surrounding tissues. When the GSV is exposed andheld by the retractor 600 of the present invention, the branches areeasily visible to the user and can be divided using bipolar cautery,hemoclips or scissors.

In the present invention, it is desired for the U-shaped attachment(s)to be completely releasable from the retractor blade. This configurationavoids having any branches of the GSV being torn or damaged. TheU-shaped attachment may be clipped onto the blade 604 such as byinserting the ends of the U-shaped attachment into corresponding slotsin the blade and engaging the ends of the U-shaped attachment with thecorresponding slots. In some embodiments, the ends of the U-shapedattachment may include outward protrusions, which are inserted intocorresponding slots in the blade while squeezing the legs of theU-shaped attachment toward each other and which engage with thecorresponding slots in the blade by releasing the legs of the U-shapedattachment. The slots in the blade may have a horizontal, vertical orangled orientation relative to the length of the blade. Other mechanismsof releasable coupling of the U-shaped attachment, such as use ofcantilever joints and other types snap-fit mechanisms, are contemplatedby the invention. In other embodiments, the U-shaped attachment may haveonly one leg permanently fixed to the retractor and the other legreleasably attached so as to allow opening and closing of the U-shapedattachment.

In yet other embodiments, one or more C-shaped attachments may be usedinstead of the U-shaped attachment(s), wherein one of the ends of theC-shaped attachment is attached to or engaged with the first surface ofthe blade, while the other end is not attached to the blade and ispositioned at a distance from the first surface of the blade. Thisconfiguration allows the GSV to be slipped into the C-shaped attachmentthrough the space between the unattached end and the first surface ofthe blade. The C-shaped attachment(s) may be releasable from theretractor blade, or in some embodiments, the C-shaped attachment(s) maybe permanently attached to the retractor blade.

Although FIG. 6 shows the U-shaped attachment being coupled to the firstsurface of the blade, in other embodiments, the span of the U-shapedattachment or C-shaped attachment may be smaller and the coupling of oneor both legs of the attachment may be to the channel cover 606. In yetother embodiments, one or more coupling mechanisms for the attachmentmay be provided at or near the tip 604 a of the blade. It is alsounderstood that the particular shape of the attachment is not limited tothe U or C shape and that other shapes may be suitable for lifting theGSV.

In accordance with the present invention, the retractor 600 of FIG. 6may be a “smart” retractor which is provided with an illuminationassembly for illuminating the operating field and/or with an imagecapturing assembly for capturing still and/or video images of theoperating field in order to allow for observation of the GSV during theharvesting procedure. In some embodiments, the illumination assembly isprovided separately from the image capturing assembly. In otherembodiments, the illumination assembly is integrated into the imagecapturing assembly, wherein the image capturing assembly includes one ormore light sources for illuminating the operating field and forilluminating an area to be captured in one or more still or videoimages.

FIGS. 8A and 8B show schematic exemplary embodiments of the “smart”retractor when viewed from the tip 604 a of the retractor blade 604 ofFIG. 7 . The “smart” retractor of FIGS. 8A and 8B includes anillumination assembly with at least one light source 812 and/or an imagecapturing assembly with a camera 814. The light source 812 may be an LEDor any other suitable light source, and in some embodiments, the lightsource may be used in combination with an optical guide (a waveguide)for conducting light from the light source. In some embodiments, thecamera 814 is an endoscope camera which is miniature in size so that itcan be attached to the retractor blade 604 without interfering with thetissues and the GSV. The camera 814 may be a waterproof, CMOS-basedvideo camera with encapsulated lighting. In one example, the camera 814is a HD waterproof endoscope video camera probe with a small diameter ofless than 1 inch, e.g., about 0.1-0.5 inch diameter, that includes aHi-Vision or Super Hi-Vision CMOS sensor and has a resolution of 2.0 MPor higher. The camera preferably has a focal distance between 0.5 and 4inches, and in this example has a focal distance between 1.2 and 2.4inches. However, the focal distance of the camera may vary depending onits configuration and desired position on the retractor blade. Thecamera may include adjustable light sources, e.g., LEDs, at the cameratip. The camera in this example may have 6-8 LEDs disposed at the tip ofthe camera and spaced around the periphery of the tip. The number ofLEDs may be varied depending on the size of the camera and the size andbrightness of the LEDs. The brightness and/or color of the LEDs may beadjustable. The camera 814 of this example includes one or more of aUSB-C connection, a Micro USB connection, a Bluetooth® connection and/ora Wi-Fi connection for connecting with an external display. In certainexamples, the camera may be compatible with any operating system, suchas Windows 7/8/10, Mac OS, Android system, etc. and may support a USBOn-The-Go (USB OTG or OTG) and USB video device class (UVC) functions.More specific examples of the camera 814 include endoscope camerasmanufactured by Depstech® including NTC85S 2-In-1 Endoscope, WiFi10 WIFIEndoscope or WIFI Borescope. Other waterproof miniature cameras aresuitable for use in the retractor of the present invention.

Although not shown, in certain embodiments, the illumination assemblyfurther includes at least one energy source, e.g., a battery, anactivation device, e.g., a removable tab, a switch, a button or thelike, and electrical connections among the activation device, the energysource and the light source(s). The construction of the illuminationassembly may be similar to the illumination assemblies disclosed in U.S.Pub. Nos. US 2016/0354072 and 2017/0245849 and U.S. application Ser. No.15/869,994, which are incorporated herein by reference.

The image capturing assembly includes an image capture apparatus, i.e.,a camera 814, which is capable of taking still and/or video images. Theimage capturing assembly may also include a storage device, e.g., amemory card, flash storage, or the like, for storing capturedimages/videos and/or a communication interface for communicatingcaptured images/videos and/or live view images/videos to one or moreoutside devices. The communication interface may be a wiredcommunication interface, such as USB or HDMI, or a wirelesscommunication interface, such as Bluetooth®, Wi-Fi or Near FieldCommunication. In certain embodiments, the camera may be capable of bothwired and wireless communication, including but not limited to USB,HDMI, Bluetooth®, Wi-Fi, Near Field Communication, etc. For example, theimage capture assembly may be connected, by a wire or wirelessly, to avideo screen, so as to transmit images during the procedure and to allowthe user to view the images on the video screen. The image captureapparatus, the storage device and/or the communication interface arepreferably housed within the same housing. In certain embodiments, theimage capturing assembly also includes one or more energy sources, e.g.,batteries, or may be electrically coupled with the one or more energysources of the illumination assembly. In yet other embodiments, theimage capturing assembly may not include any energy sources therein andmay require external power supply, e.g., via a USB connection. Forexample, during use, the image capturing assembly may be connected viathe USB connection with a display screen so that power is supplied tothe image capturing assembly from the display screen via the USBconnection and captured or live images are transmitted from the imagecapturing assembly to the display screen via the same USB connection.

In certain embodiments, the camera uses a lens carrier housing forenclosing the lens, and image sensor chip and/or lighting, such as theendoscope video camera described above, and the lens carrier housing ispermanently or releasably attached to the surface of the retractor or tothe tip of the retractor. In other embodiments, the camera may be aone-piece assembly that incorporates the lens, the image sensor chipand/or the lighting, which can be molded into the retractor blade orinto the tip of the retractor blade, or may be received in a cavityformed in the retractor blade or the tip of the blade.

In the embodiments of FIGS. 7, 8A and 8B, the retractor is modified fromthe retractor of FIG. 6 , wherein the blade includes a channel passingtherethrough, the channel cover 606 is formed on the concave surface ofthe tip 604 a and is coupled with the channel passing through the blade604. In other embodiments, the blade may include a channel along thesurface of the blade with a channel cover provided on the surface of theblade 604, similar to the configuration of FIG. 6 , and the channelcover 606 formed on the surface of the tip 604 a may be coupled with thechannel and the corresponding channel cover provided on the blade 604.In the embodiment of FIG. 8A, the light source 812 (or a waveguide whenused in combination with the light source) of the illumination assemblyis positioned at or near the open end of the channel cover 606 and isconfigured to illuminate the operating area around the tip 604 a of theretractor blade. In FIG. 8A, the camera 814 is provided outside of thechannel cover 606 and is attached to the concave surface of theretractor tip 604 a, the surface of the retractor blade and/or to theexternal surface of the channel cover 606. In some cases, the camera 814is releasably attached to or clipped or snapped onto the retractorblade, the retractor tip or the channel cover. In other embodiments, thecamera is permanently attached to the retractor. Although FIG. 8A showsthe camera 814 being provided outside the channel cover 606 while thelight source 812 is provided inside, or partially enclosed by, thechannel cover 606, in other embodiments, the positions of the camera 814and the light source 812 may be switched so that the camera 814 isprovided inside or partially enclosed by the channel cover 606 and thelight source 812 is provided outside the channel cover 606.

In the embodiment of FIG. 8A, wiring connecting the light source 812 tothe at least one energy source (not shown) can be provided between thechannel cover 606 and the concave surface of the tip 604 a and extendalong or inside the blade and into the handle of the retractor.Exemplary positioning of the wiring between the light source and theenergy source is described in U.S. Pub. Nos. US 2016/0354072 and2017/0245849. Wiring, if any, for connecting the camera 814 to an energysource (external or within the handle of the retractor) and/or to anyexternal device (e.g., display screen) may be provided along the surfaceof the retractor blade 604 outside of the channel in the retractor bladeor may be provided in the channel in the retractor blade and may extendfrom the proximal end of the blade or through the retractor handle.

In the embodiment of FIG. 8B, the light source 812 of the illuminationassembly and the camera 814 of the image capturing assembly arepositioned adjacently at or near the open end of the channel cover 606.In this case, wiring connecting the light source 812 and the camera 814are provided between the channel cover 606 and the concave surface ofthe tip 604 a, along the channel in the blade 604 or along the outersurface of the blade, and may extend into and through the handle of theretractor and/or from the proximal end of the blade.

In certain embodiments of FIGS. 8A and 8B, the positioning of the lightsource 812 and/or the camera 814 may be varied relative to the end ofthe channel cover 606. For example, either the light source 812 or thecamera 814, or both, may be positioned closer to a distal end of the tip604 a of the retractor blade. For example, in some embodiments, thecamera 814 may be positioned at the end of the tip of the retractorblade, and in other embodiments, the camera may be positioned about 1-2cm away from the end of the blade tip. In yet other embodiments, thecamera 814 may be positioned further away from the blade tip. Thepositioning of the camera 814 relative to the tip of the retractor bladeis dependent on the depth of field, the color of the illumination andthe amount of light provided by the illumination assembly. The camera814 should be positioned so as to allow clear visualization of the GSVbeing harvested while avoiding debris and fluids from the operatingregion blocking the view of the camera 814. In certain embodiments, theposition of the camera 814 relative to the tip of the blade may bechangeable, such as by sliding by a sliding mechanism along the blade orby detaching the camera 814 from one position and reattaching the camera814 at another position relative to the tip. In some embodiments, thecamera may be a self-cleaning camera that is capable of clearing anydebris or fluids accumulating on the camera lens. In certainembodiments, the camera may be water proof or liquid proof and/or may becoated with a waterproof coating, such as a silicone coating.

As mentioned above, in some embodiments, the illumination assembly maybe integrated with the image capturing assembly. For example, one ormore light sources may be provided as part of the image capturingassembly on the camera 814 or may surround the camera 814 or the cameralens so as to provide a single integrated assembly. In such embodiments,power for the integrated image capturing and illumination assembly maybe provided from an external source, e.g., via a USB cable.Alternatively, the retractor may include one or more energy sourcesprovided in the handle or near the proximal end of the blade forpowering the one or more light sources and/or the camera. In someembodiments, the integrated image capturing and illumination assemblymay selectively use power supplied by one or more energy sources in theretractor, e.g., in the handle or on the blade, for the light sourcesand/or the camera when external power is not available and use externalpower supplied from an external power source when available.

As discussed above, the “smart” retractor or harvester of the presentinvention can be used during the GSV harvesting procedure to enabledirect visualization of the GSV being harvested and to provideillumination during the harvesting procedure. In one specific example,the camera 814 of the retractor is connected wirelessly or by a sterileUSB cord to a portable ultrasound machine, such as Terason® t3200 ort3300, so that the display screen of the portable ultrasound machineacts as a monitor or display for the camera. In addition, when thecamera is connected to the ultrasound machine or any other displayscreen using the USB cord, power may be supplied to the camera via theUSB cord so that additional wires or batteries are not required foroperation of the camera. The retractor of this invention exposes the GSVand allows for better visualization of the GSV and its branches duringthe harvesting procedure.

In another embodiment, another version of a retractor 900 is shown inFIG. 14 . The configuration of the retractor 900 is similar to that ofFIGS. 6 and 7 , and similar features are shown using similar referencenumbers. However, instead of including a camera in the retractor 900,the retractor of FIG. 14 includes a tunnel 902 formed on or connected tothe blade 604 for loading a visualization device 1000, such as acystoscope, an angioscope or an endoscope. The visualization device maybe the same visualization device used for hydrodissecting the GSV underdirect vision.

As shown in FIG. 14 , the tunnel 902 is formed on the first surface 604b of the blade 604 and extends adjacent to the channel cover 606 usedfor smoke evacuation or fluid/gas delivery. The size and shape of thetunnel 902 is not limited to the shape shown in FIG. 4 and may besmaller in width, shorter or longer in length and/or may be formed usinga solid tunnel cover permanently or releasably attached to the firstsurface 604 b of the blade or using a plurality of C or U shapedattachments permanently or releasably attached to the first surface ofthe blade along the channel cover 606. In other embodiments, the tunnelmay be integrally formed with the blade, instead of using a separatecover or attachments. In some embodiments, the position of the tunnel902 may be varied. For example, the tunnel 902 may be provided on top ofthe channel cover 606 instead of to the side of the channel cover 606.

As shown in FIG. 14 , the tunnel 902 is used for loading and holding thevisualization device 1000 adjacent to the retractor blade 604. In theillustrative embodiment of FIG. 14 , when the visualization device isloaded into the tunnel, the tip of the visualization device is placednear the tip 604 a of the retractor for optimal visualization of the GSVduring harvesting. However, in other embodiments the positioning of thetip of the visualization device may be adjusted so as to provide desiredvisualization of the GSV. Although not shown, in some embodiments, alocking mechanism may be used to lock in place the position of thevisualization device in the tunnel 902 or relative to the retractorblade 604. The locking mechanism would prevent movement of thevisualization device relative to the retractor during the GSV harvestingprocedure.

Although the tunnel 902 in the retractor of FIG. 14 is used for loadingthe visualization device, in other embodiments, the tunnel can be usedfor holding other devices, as needed. In the retractor of FIG. 14 ,since a camera is not required to be part of the retractor, a smallersize of the retractor and lower manufacturing cost can be maintained.However, in some embodiments, the configuration of the retractor of FIG.6 may be modified to include the tunnel for loading the visualizationdevice. In such embodiments, the retractor would include a camera, asshown in FIGS. 8A and 8B, and would also be capable of loading avisualization device, or other devices, as needed.

In certain embodiments, instead of using the retractor of FIGS. 8A-B and14, the hydrodissector 1200 of FIGS. 15-21 or the hydrodissector withthe shovel-shaped or spatula-shaped tip described above may be usedduring the harvesting procedure. In these embodiments, the camera of thehydrodissector provides direct visualization and illumination of the GSVbeing harvested. One or more of the fluid ports 1240, 1240 a, 1240 b ofthe hydrodissector may be used for washing the GSV with fluid, such asthe sodium bicarbonate solution or a solution of one or more medicationsmentioned above, and/or for providing a CO₂ infusion to the GSV.Furthermore, if needed, suction may be provided to the GSV using one ofthe fluid ports 1240 a, 1240 b to remove any excess fluids.

As discussed above, in some embodiments, the hydrodissector of FIGS.15-21 has interchangeable tips or interchangeable bodies with differenttips, so that the angled tip 1230 or the body with the angled tip of thehydrodissector in FIGS. 15-21 may be removed and replaced with anothertip, such as a shovel-shaped or spoon-shaped tip, or another body with adifferent tip, in order to convert the hydrodissector into aretractor/harvester. As also discussed above, the shovel-shaped orspoon-shaped tip includes a camera provided on its concave surface anddirected so as to provide direct visualization of the GSV when the tipis used to retract tissue around the GSV. In certain embodiments, thecamera is angled between 90 and 180 degrees relative to the surface ofthe shovel-shaped or spoon-shaped tip. In addition, as in theembodiments of the retractor in FIGS. 6 and 7 , one or more C-shaped orU-shaped attachment(s) may be removably attached to the shovel-shaped orspoon-shaped tip or to the tubular-shaped body so that the C-shaped orU-shaped attachment(s) is used for lifting the GSV. For example, one ormore C-shaped or U-shaped attachments may be removably attached on theconcave side of the shovel-shaped or spoon-shaped tip. The one or moreC-shaped or U-shaped attachments may be attached at other locations onthis convertible hydrodissector so as to optimize lifting of thehydrodissected GSV without causing damage thereto.

In certain embodiments, other devices that prevent trauma to the GSV andpreserve the GSV may be utilized for vein harvesting in addition to theabove-described retractor and/or hydrodissector. For example, a VeinPreparation Kit manufactured and sold by VasoPrep Surgical(vasoprep.com) may be used during harvesting the GSV. VasoPrep's VeinPreparation Kit includes a non-toxic surgical marking pen that preservesendothelial function, a pressure relief assembly that automaticallylimits distention pressure during preparation of the vein, a bulldogclamp for atraumatic vein occlusion, a vein cannula and cannulaintroducer assembly and other components such as syringes and temporaryvein storage cup. Either some or all of the components of this kit maybe used during GSV harvesting. Other techniques and devices whichpreserve the vein during harvesting are described in U.S. Pat. No.8,691,556, assigned to Vanderbuilt University, which may be used duringGSV harvesting. The entire disclosure of the '556 patent is incorporatedherein by reference.

In accordance with the present invention, a kit for performing the MINTprocedure may be provided in order to supply the devices needed forperforming the MINT procedure. In certain embodiments, the kit includesone or more of the following items: one or more needles for use inhydrodissecting the GSV, one or more disposable venous hydrodissectorshaving a pencil tip and/or the cone-shaped blunt tip, at least onedisposable “smart” retractor/harvester with one or more U-shaped and/orC-shaped adapters, disposable clip appliers, such as clip appliersmanufactured by Microline Surgical, clips, such as hemoclips, disposablescissors, disposable hook(s), disposable cauteries, disposableelectrode(s) and tumescent fluid for use in hydrodissection. The kit mayalso include medication solutions for use after hydrodissection andother solutions and/or devices for use during the MINT procedure. Thekit may also include the hydrodissector and sheath introducer shown inFIGS. 10-13 , and/or the hydrodissector of FIGS. 15-19 and/or FIGS.20A-C and/or FIGS. 21A-C as well as interchangeable tips orinterchangeable bodies with different tips for the hydrodissector ofFIGS. 15-19, 20A-C and/or 21A-C to enable conversion betweenhydrodissecting functions and harvesting functions. Moreover, the kitmay also include a vein preservation kit, such as a Vein Preparation Kitmanufactured by VasoPrep (www.vasoprep.com) that includes a surgicalmarking pen, a pressure relief assembly, a bulldog clamp for atraumaticvein occlusion, a vein cannula and cannula introducer assembly and othercomponents such as syringes, temporary vein storage cup, etc.

Using Endoscopic ASVAL, a Modification of the Mint Procedure to TreatVaricose Veins

The most popular method for treating varicose veins involves the removalor destruction of the Great Saphenous Vein (GSV). This technique isbased on the “descending theory” of the etiology of varicose veins,which was first posited by Trendelenburg in 1894, when patientspresenting for treatment had far advance disease. Today, the majority ofpatients treated for varicose veins have far milder disease with GSVsthat do not have to be sacrificed for the treatment to be effective.This more modern treatment is based on the “ascending theory” of theetiology of varicose veins. The “ascending theory” posits that varicoseveins start in the more superficial, thin wall veins and the GSV onlybecomes pathologic once a large venous reservoir develops. This allowsthe majority of patients to be treated by meticulous, ultrasound guided,phlebectomy such as the ASVAL technique, which can prevent the loss ofthe GSV. According to the CEAP Classification System, there are sixlevels of venous disease. The ASVAL method works well for C-2 levelvenous disease and for some C-3 level venous disease. However, forpatients with more far advanced disease, the ASVAL method alone will notsave the GSV, and this patient group would be an ideal group ofcandidates for Endoscopic ASVAL of the present invention.

The Endoscopic ASVAL procedure starts exactly as the MINT proceduredescribed above, with ultrasound guided hydrodissection of the GSV fromjust below the knee at Boyd's perforator to the groin. A small incisionis made at the knee and the hydrodissection is started as in the MINTprocedure. The position of the incision and hydrodissection may beadjusted as needed for the procedure. The Endoscopic ASVAL procedurediffers from the above-described MINT procedure in that the sidebranches which are varicosed and incompetent perforators are divided,while branches which are normal, healthy and competent perforators areleft alone and are not divided. In this way, the varicosed branches ofthe GSV are divided while leaving the healthy branches that arecompetent perforators intact to ensure long-term patency of the GSV.

The abnormal branches to be divided can be identified by ultrasoundpreoperatively with the patient in a standing position. Once theabnormal vessels have been divided, the Endoscopic ASVAL procedure isfinished with the GSV left in situ. The knee incision is closed and thepatient is placed in a thigh length compression stocking. Compressiontherapy is continued for several weeks post-op to ensure that the GSVremains undilated while the cicatrix around the vein forms. The cicatrixformed around the GSV should act as an exoskeleton at the time it isharvested for bypass. The use of exoskeletons around venous bypasses inanimal and human studies have resulted in improved hemodynamics andreduced Vein Graft Failure (VGF). At the time of bypass, the GSV and itssurrounding cicatrix can be harvested using the principles developed byDr. Keith Delman in performing minimally invasive lymph node groindissection in patients with metastatic malignant melanoma.

The Endoscopic ASVAL procedure and any future harvesting of the GSV canbe performed using the same equipment as the above-described MINTprocedure, namely the echogenic needle and/or venous hydrodissector, theportable ultrasound, such as Terason t3200 or t3300, and/or thevisualization device, and the “smart” retractor, all of which aredescribed above. These procedures can all be done under local tumescentanesthesia in an outpatient setting, thus reducing the complexity andcost of the procedures and reducing patient recovery time.

As with the above-described MINT procedure, the Endoscopic ASVAL allowsthe adventitia of the GSV to be treated with drugs such as platelet richplasma or stem cells to strengthen the wall of the GSV, since weaknessof the vein wall is thought to be a primary cause of varicose veins.These and other drugs, as well as gene therapy, can be delivered to theGSV over several days, weeks or months, using existing technology. Forexample, drug therapy, stem cell therapy and/or gene therapy can bedelivered to the GSV on a permanent or a bioabsorbable drug elutingstents. Other drugs, such as the ones mentioned herein above used in theMINT procedure, may be applied to the GSV to promote strengthening ofthe venous wall, preventing thrombosis and preventing damage to the GSV.

FIG. 9A shows a GSV after undergoing the Endoscopic ASVAL proceduredescribed above. As shown in FIG. 9A, the procedure is performed througha 2-cm incision preferably in the knee region to hydrodissect the GSVbetween the knee and the groin. As also shown in FIG. 9A, incompetentperforator and varicosed vein branches are ligated while competentperforator branches are left intact. In other embodiments, the positionof the incision and the size thereof may be different, and in someembodiments, the portion of the GSV treated may be between the knee andthe ankle, or may be the full length of the GSV. The procedure of FIG.9A may be modified to use a diaphragm with a one-way access port, asdescribed above with respect to FIGS. 22-26 , and to perform multiplehydrodissection passes.

FIG. 9B shows a GSV after undergoing the Endoscopic ASVAL procedure andhaving bioabsorbable drug eluting stents applied thereto. As shown, thestents are applied to the hydrodissected GSV and the ligated branches inorder to deliver drug therapy, stem cell therapy and/or gene therapy tothe GSV. In the embodiment shown in FIG. 9B, the stents are not appliedto the competent perforator branches, which are not ligated. In otherembodiments, however, the stents may be applied to all branches,including the competent perforator branches and the ligated branches, orto selected branches of the GSV, as needed.

The above-described MINT procedure and the Endoscopic ASVAL procedurecan also address a concern that thrombus might develop in the GSV at thetime of hydrodissection. This may be prevented by giving the patient onedose of therapeutic Lovenox two hours prior to the hydrodissection. Thiswould protect against the possibility of any intraluminal clotsdeveloping during the hydrodissection and the effect of the Lovenoxwould be completely neutralized by the time GSV harvesting is carriedout at the time of the CABG. In certain cases, standard EVH procedure aswell as the MINT procedure described above can cause intra andpostoperative bleeding at the saphenectomy site leading to hematomaformation and increased leg wound complications. This complication canbe avoided by infusing tumescent fluid containing isotonic sodiumbicarbonate with Lidocaine and epinephrine into the potential spacecreated by the saphenectomy at the time of the harvesting. This wouldalso eliminate any possibility of intra or postoperative bleedingnecessitating the use of drains in the leg.

While the above descriptions of the MINT procedure and the EndoscopicASVAL procedure direct the use of a needle, such as an echogenic spinalneedle, or venous hydrodissector to perform the hydrodissection underultrasound guidance or under direct vision to make this procedure asminimally invasive as possible, other effective imaging techniques areavailable. For example, if the sonographic skills of the averagePhysician Assistant performing this procedure do not allow them tosafely use an echogenic needle, a rigid 2 mm cannula can be easilyplaced in the saphenous space with a 7-French introducer sheath. Thisblunt tipped 2 mm infusion cannula completely eliminates any potentialdamage to the GSV at the time of hydrodissection secondary to a sharptipped echogenic spinal needle. Alternatively, the venoushydrodissectors described above can be used instead of the needle.

The above-described MINT procedure and the Endoscopic ASVAL proceduresolve a number of problems typically associated with vein dissection andharvesting procedures. First, the MINT procedure and the EndoscopicASVAL procedure solve a problem of leg wound complications that occurwith open vein harvest techniques by using a minimally invasivetechnique performed through a 3 cm incision. Second, the MINT procedureand the Endoscopic ASVAL procedure solve a problem of blunt trauma tothe GSV that occurs during harvesting because hydrodissection of the GSVeliminates all blunt trauma during harvesting.

Another common problem occurring in conventional procedures is thrombus,both macro and micro, which occurs in about 67% of GSVs harvested withstandard EVH procedures. In the present invention, addition of lowmolecular heparin to the perivascular space has been demonstrated topenetrate the vessel wall down to the endothelium. Also, addition ofaspirin to the perivascular space has a direct protective effect on theendothelium which reduces endothelial denudation and thrombosis. TheMINT procedure and the Endoscopic ASVAL procedure also solve a problemof spasms of the GSV. Specifically, addition of anti-spasmotic agentssuch as Papaverine or nitroglycerine-verapamil solutions, to thetumescent fluid prevents spasms of the GSV.

When the hydrodissection of the GSV is performed about 24 hours beforeperforming a lower extremity bypass, the fascial space surrounding theGSV has to be gently re-expanded with the tumescent fluid solutioncontaining the above-described medications, i.e., aspirin, low molecularweight heparin, Papaverine, etc. This is necessary to ensure theperivascular delivery of the aspirin, low molecular weight heparin andanti-spasmotic agents at the moment the harvesting of the GSV isstarted. This prevents the initiation of thrombosis, which is known tobe the first step leading to intimal hyperplasia and the chief cause ofvein graft failure. Therefore, at the time of vein harvest for eitherCABG or the lower extremity bypass, the hydrodissector and/or retractordescribed above used for harvesting is required.

The present invention also solves a problem of a toxic environmentsurrounding the GSV. In the present invention, Plasma Lyte A, which is amajor component of the tumescent fluid, has a pH of 7.4 compared toNormal Saline with a pH of 5.6, which is known to be toxic to the GSV.Thus, the tumescent fluid used during the MINT procedure and theEndoscopic ASVAL procedure avoids a toxic environment surrounding theGSV. In addition, the present invention solves the problem of a toxiceffect of CO₂, which is a further cause of acidosis leading toendothelial damage. Specifically, the MINT procedure and the EndoscopicASVAL procedure use an open CO₂ system and the Plasma Lyte A solution isa buffered salt solution which would neutralize the effect of CO₂.

The MINT procedure and the Endoscopic ASVAL procedure of the presentinvention solve a problem of inexperienced physician assistants (PAs)damaging the GSV during harvesting, thus leading to inferior GSV patencyrates. In the present invention, for lower extremity bypass procedures,where hydrodissection is performed 24 hours pre-op with an ultrasoundguided spinal needle or with an ultrasound and/or direct vision guidedhydordissector, the PA can perfect the hydrodissection technique onvenous patients that are having their GSVs ablated. PAs would be allowedin a cardiac suite after video confirmation of mastery of this techniqueon venous patients. Moreover, for CABG patients, where the MINTprocedure takes place immediately prior to bypass, the hydrodissectorsdescribed above feature real-time visualization of the GSV andultrasound monitoring of the hydrodissection will ensure complete andatraumatic dissection of the GSV. As a result, this process eliminatesthe learning curve needed for the standard EVH procedures.

Moreover, the MINT procedure and the Endoscopic ASVAL procedure of thepresent invention solve a problem of post-operative hematomas at harvestsite. In the present invention, once the GSV is harvested, the site isinfiltrated with tumescent fluid consisting of isotonic sodiumbicarbonate with xylocaine and epinephrine added. During this procedure,no drain is used and a water tight closure is performed. Thigh lengthstocking and Ace wrap is applied to the patient's extremity prior toleaving the operating room.

Finally, performing hydrodissection of the GSV, as described above,about 24 hours prior to a lower extremity bypass allows the surgeon toperform this complex vascular reconstruction under straight localanesthesia since all of the dissection has already been completed theday before. As a result, the present invention substantially reduces theoccurrence of surgical trauma, and the surgical trauma for thisreconstruction is the same as for a simple embolectomy. Therefore, theprocedures of the present invention reduce post-operative morbidity andmortality rates.

In all cases, it is understood that the above-described arrangements aremerely illustrative of the many possible specific embodiments whichrepresent applications of the present invention. Numerous and variedother arrangements, including use of different materials and variousconfigurations of components of the retractor, can be readily devisedwithout departing from the spirit and scope of the invention.

INCORPORATION BY REFERENCE

The present application claims priority to U.S. Provisional PatentApplication Nos. 62/533,714 filed on Jul. 18, 2017, 62/640,892 filed onMar. 9, 2018 and 62/683,376 filed Jun. 11, 2018, the disclosures ofwhich are incorporated herein by reference.

We claim:
 1. A hydrodissector for hydrodissecting a vascular target, thehydrodissector comprising: a handle; a shaft extending from the handleat an angle and including a tip at a distal end thereof; at least oneport provided at the tip and configured to be coupled to a fluid supplyand to eject fluid from the at least one port into the space between thevascular target and surrounding tissues to dissect the vascular targetfrom the surrounding tissues, the at least one port being sized toprovide sufficient pressure and velocity to dissect the vascular targetfrom the surrounding tissues, wherein a length of the shaft isconfigured for insertion into an incision to atraumatically hydrodissectthe vascular target from the surrounding tissues, and wherein the shaftis configured to releasably couple with one or more hook-shapedattachments configured to lift the vascular target after the vasculartarget is dissected from the surrounding tissues.
 2. The hydrodissectorin accordance with claim 1, further comprising one or more hook-shapedattachments configured to releasably couple with the shaft.
 3. Thehydrodissector in accordance with claim 2, wherein the one or morehook-shaped attachments comprise one or more of C-shaped attachments andU-shaped attachments.
 4. The hydrodissector in accordance with claim 2,wherein the one or more hook-shaped attachments are configured to snapfit with the shaft.
 5. The hydrodissector in accordance with claim 2,wherein the one or more hook-shaped attachments are configured to coupleto an external wall of the shaft and to extend transversely from theexternal wall of the shaft.
 6. The hydrodissector in accordance withclaim 1, wherein the tip is configured to accommodate an image capturingassembly to provide direct visualization of the vascular target duringhydrodissection.
 7. The hydrodissector in accordance with claim 6,wherein the at least one port is external to the tip and is providedadjacent to the tip, and the tip is configured to fully enclose theimage capturing assembly.
 8. The hydrodissector in accordance with claim6, wherein the at least one port is provided in the tip and the tip isconfigured to substantially enclose the image capturing assembly.
 9. Thehydrodissector in accordance with claim 1, wherein the shaft includes anelongated body and the tip is removably attached to a distal end of theelongated body so as to be interchangeable with one or more other tips.10. A hydrodissector for hydrodissecting a vascular target, thehydrodissector comprising: a handle; a shaft extending from the handleat an angle and including a tapered tip at a distal end thereof; atleast one port provided at the tapered tip and configured to be coupledto a fluid supply and to eject fluid from the at least one port into thespace between the vascular target and surrounding tissues to dissect thevascular target from the surrounding tissues, the at least one portbeing sized to provide sufficient pressure and velocity to dissect thevascular target from the surrounding tissues, wherein a length of theshaft is configured for insertion into an incision to atraumaticallyhydrodissect the vascular target from the surrounding tissues, andwherein the tapered tip does not include a dissecting edge for bluntdissection.
 11. The hydrodissector in accordance with claim 10, whereinthe tapered tip is one of transparent and translucent.
 12. Thehydrodissector in accordance with claim 10, wherein the shaft comprisesan elongated body with a bore therethrough and the tapered tip isconfigured to enclose a bore opening in a distal end of the elongatedbody.
 13. The hydrodissector in accordance with claim 10, wherein thetapered tip is configured to accommodate an imaging lens to providedirect visualization of the vascular target during hydrodissection.